Primate Cognition, Communication and Culture

Question 1

What is cognition

Answer 1

the mental action or process of acquiring knowledge and understanding through thought, experience, and the senses

Question 2

How can a thought process in cognition be summarised

Answer 2

first, perception of external stimuli, followed by encoding the information in the brain that leads to judgement, which is then followed by actions and responses

Question 3

Define intelligence

Answer 3

Ability to easily learn or understand things and to deal with new and difficult situations

Involves the notions of adaptability and flexibility

Question 4

What does ‘cognitive abilities’ encompass?

How can cognitive abilities be studied

Answer 4

both cognition and intelligence, and includes the capacities to learn, to understand causality, to reason, to memorize and process memories and to communicate, among many other abilities

by behavioural expressions that reflect their strength and presence, such as behavioural flexibility, behavioural complexity, modifications of the environment, manipulation of objects or of people.

Question 5

When do we consider species to be intelligent?

How would this relate to their cognitive abilities ?

Answer 5

species that shows a high behavioural repertoire, or shows the ability to
manipulate conspecifics, is considered as intelligent, and thus is inferred to have developed higher
cognitive abilities.

Question 6

What are the 2 key types of cognition

What does this splitting of cognition assume

Answer 6

Social cognition (How information in and from social contexts are acquired, processed and used)

physical cognition (How information about the physical world are acquired, processed and used)

specific selective pressures have shaped specific cognitive abilities.

Question 7

What are 3 types of physical cognition

Answer 7

Spatial cognition
Timing cognition
Numerical cognition

not an exhaustive list

Question 8

What are 3 types of social cognition

Answer 8

Social learning
Theory of mind
Social emotion

not exhaustive

Question 9

Give an example of non primates showing specific adaptions in cognitive abilities

Answer 9

, in the Western scrub-jay, a corvid living in North-America, individuals display amazing spatial memory, as they are able to remember up to 30.000 food cache locations; they also can retrieve fast-decaying food quicker, so they have an understanding on how long a food will last; they are also able to observe others and pilfer their caches, and they can deceive stealers through re-caching or by faking caches. These birds have a better spatial memory and social intelligence than most primates.

Question 10

What are the 2 main schools of cognitive theory

Answer 10

the information-processing

school, (Sternberg) and the assimilation and accommodation school (Piaget)

Question 11

What does the information processing theory of cognition assume

Answer 11

information is processed by the

brain, like a computer would do, rather than being automatic responses to a stimulus.

Question 12

How does the information processing theory of cognition try to understand thought

Answer 12

attempts to understand the thoughts and reasoning processes by comparing the mind, or the brain, to a sophisticated computer system designed to acquire, process, store and use information in specific ways: here, the mind functions like a biological computer responsible for analysing information from the environment.

In information-processing, logic and neuronal causality are important.

Question 13

How does Piaget’s theory try to understand cognition

Answer 13

Assimilation: interpreting the world based on previous experience (person‘s internal model)
Accommodation: changes to the internal model by adjusting to experience

in Piaget, subjectivity, experience and flexibility are important

Question 14

What is comparative cognition

What is an advantage of this

Answer 14

the study of the mechanisms and origin of cognition between various species.

It has the advantage to investigate the proximate mechanisms, or how information is processed and used, but also to have an ultimate approach, by comparing closely related species to tackle the evolution of cognition.

Question 15

How is comparative cognition studied

What are the advantages and disadvantages of each method

Answer 15

Lab experiments:
++ controlled conditions, can narrow down to specific tasks, usage of replicable paradigms
- - lack of ecological relevance, captive populations

Field studies:
++ ecologically relevant
- - experiments difficult to realize, observations often anecdotical, hard to control all parameters, ethical issue

Question 16

How does primate brain size relate to cognitive abilities

Answer 16

Deaner (2007) found across all primate groups, overall primate brain size is positively correlated with cognitive abilities

Question 17

What are the key hypotheses for the evolution of cognition across primates?

Answer 17

Ecological-intelligence hypothesis

Social-intelligence hypothesis

Machiavellian intelligence hypothesis

Cultural intelligence hypothesis

General intelligence hypothesis

Question 18

Describe the ecological intelligence hypothesis

Answer 18

main selective pressure for large
brains and high cognitive abilities is ecological, mostly food resources

the challenges primates face are to find, remember, and access food

Question 19

What cognitive abilities are associated with the ecological intelligence hypothesis

Answer 19

→ spatial memory
→ associative learning (the association between external clues and food locations or food timing)
→ explorativeness

Question 20

How well do chimps remember food locations

Answer 20

Wild chimpanzees remember the locations of food resources up to three years after their last visit

Question 21

How are locations arranged in a chimp brain?

What does this mean?

Answer 21

within a mental mal, which can be manipulated and orientated depending on where the individual is located. Chimpanzees, thus, do not need to use landmarks, they have a Euclidian map.

Question 22

How did Normand (2009) show chimps have a Euclidian map of food locations

Answer 22

This has been shown by how chimpanzees approach food locations, which takes place from many directions, with a decrease of travel speed as the location gets closer

Question 23

How does a marmosets location system/mental map compare to chimps

Answer 23

marmosets also have a Euclidian map, as they approach the same feeding tree from several directions. These marmosets feed on up to 13 different trees every day, and across a year they feed on up to 150 species of trees.

Question 24

Do all primates have Euclidian maps

Answer 24

No
other primates use route-based maps and
landmarks, meaning they will always use the same routes from one location to the next, and they use
particular marks in the landscape to find their way

Question 25

Give an example of primates using landmarks

Answer 25

In two species of lemurs, individuals travel from one food patch to the next neighbouring food patch, which most likely are visible from the first location. Second, they travel in straight lines and show a
lot of backtracking, where they use the same routes on the way back. In these species, their traveling
patterns suggest a landmarks usage, but they may actually have a Euclidian map which usage is
limited due to the paucity of substrates and traveling limitations due to the topography

Question 26

How does diet affect brain size according to the Ecological intelligence hypothesis

Answer 26

fruits =

• dispersed
• seasonal

leaves=

• evenly distributed
• not seasonal

Consequently, these food types pose different ecological and cognitive challenges, where searching and finding fruits is much more challenging than searching and finding leaves. A main consequence of this differential is that frugivore species have larger brains than folivore species

Question 27

Can we predict brain size from diet

How does this compare with performance in cognitive tasks?

Answer 27

There is plenty of evidence that primate brains can be predicted by their diet, with frugivore having larger brains than omnivores, which have larger brains than folivores

habitat generalists outperform habitat specialists in cognitive tasks

Question 28

What are habitat generalists

Answer 28

Generalists include species that can thrive in many different types of habitats,
while specialists are constrained by living in specific environments and habitats

Question 29

Why does the approach of ecological specialisation rather than diet specialization challenges the view of frugivore versus folivore when it comes to cognitive ability

Answer 29

what seems to matter is the habitat rather than the diet because ecological specialization with regard to habitat, not to diet, explain observed cognitive differences.

Question 30

Give a summary of the relationships between ecological factors

Answer 30

• Primate brain size predicted by diet: frugivore > omnivore > folivore
  (DeCasien et al., 2017)
• Habitat generalists outperform habitat specialists
  → BUT ecological specialization with regard to habitat, not to diet, explain observed cognitive differences
  Henke von den
  Malsburg et al., 2020

Question 31

What hypothesis has The ecological intelligence hypothesis been directly linked to

Answer 31

the extractive foraging hypothesis

Question 32

What is the the extractive foraging hypothesis

Answer 32

proposed to explain the higher cognitive abilities of great apes and is also proposed for high cognitive abilities of humans.
Here, the main idea is that high cognitive abilities of great apes are adaptations for exploiting a variety of high-energy embedded foods through intelligent tool use and its social transmission

Question 33

Does the extractive foraging hypothesis just apply to primates

Answer 33

no

also used to explain high cognitive abilities in some species of birds, like crows and parrots.

Question 34

According to the extractive foraging hypothesis, what is the pathway from apes to humans in terms of cognition

Answer 34

in great apes, embedded food is seasonal, and apes learn to use tools to dip, fish, excavate, open and remove food stuff which are embedded, such as termites, ants, honey and nuts.

While in great apes, reliance on tools is only seasonal, as can be tool use to crack nuts, in human evolution, it is hypothesized that the reliance on tools became more and more important all year-round, making the usage of tools indispensable in
foraging strategies

Question 35

How does the extractive foraging hypothesis become more of a socio-ecological hypothesis

How does it also help explain advanced cognitive abilities

Answer 35

using tools to access to food and to feed makes that feeding requires complexity in food processing and so this complexity requires social transmission of
techniques

also, the hypothesis proposes that technological prowess and dexterity require advanced cognition, for the motor control to manipulate objects and for the understanding of sequences of actions.

Question 36

How likely is it that intelligence is linked to tool use in primates

Answer 36

Species in which a precision grip exists show tool use in feeding, and those of which brain size has been measured show a developed parietal area in their neocortex which is the area that enables this precision in tool manipulation

using g as a measure, it appears not only apes appear cleverer than the rest, but also a few other species like macaques, capuchins and baboons, who also show tool use in the wild and in captivity.

Parker, 2015

Question 37

What cognitive ability does the extractive foraging hypothesis rely on

Which types of primates have this ability

Answer 37

object permanence

all primates have some understanding that things continue to exist out of sight and species that do more extractive foraging have better object permanence

Question 38

Does tool use imply primates who use them understand causality?

Answer 38

All primates that use tools show that they select tools according to functional properties and that they manufacture tools to make it functional for the task, suggesting that they understand the causality behind its usage.

Question 39

Give an example of how chimps can understand the physical properties of tools

Answer 39

wild chimpanzees select nut-cracking tools according to multiple physical properties (weight, hardness, size, density); their selection of weight depends on other tools properties and on context; adjustment of selection to forthcoming transport reflects a planning of future actions

Question 40

Give an experiment showing chimp choice about tools

Answer 40

in chimpanzees with the number of transports of nutcracking tools as function of the distance
of transport, for stones on the top and for wooden hammer on the bottom. Stones are transported over longer distances than wood, because stones are easier to transport due to their size, despite a heavier weight. Walking around
with a stick in the dense forest is not easy, as compared to carrying a stone in the hand. So, they clearly plan which tool to pick depending on where they will use it. Similarly, the probability to choose a tool as function of its weight shows that when the anvil is in a tree, lighter hammers are picked; when the anvil is on the ground, heavier hammers are picked and used.

Sirianni et al., 2015

Question 41

Describe the Social intelligence hypothesis

Dunbar, 1992/8

Answer 41

Individualized relationships organized in a network

Various relationship attributes: dominance, bond, kinship…

Keep track of own and others’ interactions

→ advanced cognition needed for
cooperation, competition and social
strategizing

Question 42

What does Dunbar base the rationale of the social intelligence hypothesis on

Answer 42

life in group increases
complexity

due to this high social complexity of primate groups, the social intelligence corresponds to the comprehension of identity, kinship, and relative rank, and this intelligence is expressed by showing flexible behaviour according to who does what and who does what with who.

Question 43

What are some of the social complexities of living in a group

Answer 43

dominance hierarchies, with the notion of relative rank, where individuals have to understand the rank of oneself, but also the rank of others and of their relatives

triadic interactions, which involve more than two individuals such as in coalitions, re-directed aggressions, third-party affiliations and third-party relationships.

fission-fusion

Question 44

Give evidence primates have the intelligence to know and remember relative rank

Answer 44

layback experiments have shown that baboons recognize that a dominance hierarchy can be sub-divided into family groups. After an aggression between two females, researchers emitted call sequences mimicking dominance rank reversals between families and within families

duration of looking toward the speaker is longer when dominance is reversed as compared to not reversed, showing the surprise effect and interest of the baboon.

this duration is longer and different when reversal occurs
between families than within families as reversal of rank within families is common (so not so surprising), while between families
it rarely occurs - understand membership in higher order groups, eg families or caste

Question 45

Why are triadic interactions thought to increase complexity

Answer 45

it decouples rank and power

strategizing individuals must base their decisions not only on observable clues (e.g., large body size or the rank of a single individual) but also on differentiated relationships due to number of coalition partners

Question 46

Why do individual primates not only monitor their own grooming relationships

Answer 46

coalitions are thought to be intimately linked with grooming, since grooming reinforces social bonds needed for coalitions.
Consequently, individuals have to monitor not only their own relationships but also the relationships, in particular grooming, of other individuals.

Question 47

What is redirected aggression

What cognitive ability does this show

Answer 47

where an aggressed individual will tend to re-direct this aggression toward a family member of the aggressor, showing they understand kin relationships of others.

Question 48

Other than redirected aggression, what is another way to see primates understand kinship

Give evidence primates do this

Answer 48

n third-party reconciliation, where a kin individual of the
aggressor reconciliates with the one aggressed on behalf of the aggressor.

Wittig et al., 2007, using playback experiments, baboons that just got threatened respond more strongly to peaceful grunt emitted by kin members of the aggressors than to control vocalizations, and they increased their proximity postconflict after hearing peaceful grunts from kin members.

Question 49

What skill that primates have shows they understand many attributes of individuals

Give an example of this

Answer 49

Third-party relationships such as recruitment of coalition partners

male bonnet macaques use information about third-party rank relationships when they recruit support from other males.
Males consistently chose allies that outranked themselves and their opponents and made such choices considerably more often than would be expected by chance alone. High-ranking males received more solicitations for support in coalitions than lower-ranking males

Question 50

What characterises fission fusion

What makes it complex

Answer 50

variable sub-grouping that change over time and space

hard to keep tracks of who hangs out with who and who does what with who. Fission-fusion introduces uncertainty in the relationships.

Question 51

What is a consequence of living in fission-fusion societies?

Answer 51

promotes inhibitory control. Inhibition, such as waiting before getting a reward, is thought to be a high cognitive ability, since inhibition is the suppression of prepotent but ineffective responses in a changing social environment

Question 52

Does the data support fission fusion primates having better inhibitory control

Answer 52

A comparative analysis of inhibitory control of primates shows that fission-fusion species show higher inhibitory control than non fission-fusion species.

Amici et al., 2013

Question 53

Why does Dunbar highlight the neocortex in particularly (function)

How does it compare bewteen primates

Answer 53

Neocortex: seat of cognitive process such as reasoning and consciousness

When the size of the neocortex is related to the rest of the brain, apes have a higher neocortex
than old world monkeys, themselves bigger than new world monkeys, themselves bigger than
prosimians. N

Question 54

Why does Dunbar argue the ecological intelligence hypothesis is incorrect

Answer 54

neocortex is not
related to percentage of fruits in the diet

neocortex is not related to home-range size

Question 55

Why does Dunbar argue the extractive foraging hypothesis is incorrect

Why is Dunbar’s seemingly correct

Answer 55

neocortex size is not related with extractive foraging

neocortex is strongly related with group size, a proxy for social complexity, making the argument that high social complexity, due to high group size, is positively associated with high cognitive abilities, due to large brain sizes in larger groups.

Question 56

What is another way to measure social complexity, other than group size ?

How does this relate to neocortex size

Answer 56

the size of grooming
cliques, which is the number of social partners used during grooming sessions, and the size of
grooming networks, which the number of links between partners

Neocortex relative size is larger in species with larger grooming cliques; grooming networks are larger for larger groups, and larger grooming cliques are found in species with larger grooming networks. This relationships between brain size and grooming networks means that when more individuals are involved in social relationships, keeping tracks of these relationships require advanced cognitive skills, pushing for an evolutionary increase of brain size.

Question 57

What might contradict Dunbar’s findings regarding neocortex being the best proxy for intelligence

Answer 57

Deaner et al., 2007 found that Cognitive abilities better predicted by overall brain size than by neocortex size

Question 58

Give an example of supposedly complex social behaviours that can be explained by simple rules of thumb

Answer 58

eg sooty mangabeys

• higher-ranking individuals are more likely to stay near two other groomers than low-ranking ones
• higher-ranking contestants in conflicts are more likely to get support than low-ranking and high-ranking individuals are more solicited for support than low-ranking ones

These behaviours seem complex, because they involve more than two partners and because they imply understanding of relative rank relationships

However, these results also can be explained by simple rules such as “intervene only when you outrank the target”, “always intervene on behalf of the aggressor”, “always support the high-rank”, all simple rules of thumb which would imply only understanding of own rank as compared to another individual, rather than processing third-party relationships and related ranks.

Question 59

Why may brain size not be a good indicator of intelligence

Answer 59

intelligence in insects, where very few neurons allow them to complete relatively complex tasks

Question 60

What is the idea behind brain enlargement in the social intelligence hypothesis

Answer 60

big brains, neurons are larger due to physiological constraints, but also that in large brains neuronal circuits are replicated, allowing a better precision, a better perception and a better storage capacity

Question 61

What are some of the higher abilities displayed by apes

Answer 61

include computational thought and ToM

Question 62

What does the Machiavellian intelligence hypothesis state

Answer 62

in addition to social complexity, intense social competition leads to the development of Machiavellian social strategies to achieve higher social status and fitness, and that this Machiavellian intelligence acts through using manipulation and deception. These abilities, to manipulate and deceive, require mental representations only seen in apes and humans.

Question 63

Summarise ToM

Answer 63

the ability to understand others mental states and intentions, but also self-awareness

Question 64

How do we assess self awareness

Which primates are self aware

Answer 64

mirror experiments
We put a mark on the face of a primate, and in front of a mirror we see if those individual notices the mark. If they do, they are aware that what they see is themselves, if they don’t, we conclude they are not self-aware

Apes: yes Monkeys: no

Question 65

Can primates understand what others are seeing (other than apes)

Answer 65

Macaques understand what others are seeing since macaques follow the gaze of others, and this ability is shared by many other animals such as capuchins in primates, but also goats and dogs.

Question 66

Name some particularly high cognitive skills that bonobos, chimps, and orangutans possess (4)

Answer 66

self-awareness and representation,
comprehension of other’s knowledge,
comprehension of false beliefs
deception

Question 67

which other hypothesis has been developed in parallel with the Machiavellian intelligence hypothesis to address great apes’ intelligence?

Answer 67

Cultural intelligence hypothesis

Question 68

What is the key idea with the cultural intelligence hypothesis

Answer 68

social learning is more efficient than individual exploration, which should lead to learning of skills much faster with social learning than without. Also, an individual’s repertoire of learned skills is boosted by frequent social learning opportunities. Species with frequent opportunities for social learning can afford to increase cognitive power, which in consequence should lead to more heavily cultural species being more intelligent

Question 69

Summarise the sources of an individual’s set of learned skills as acquired during development according to the cultural intelligence hypothesis

Answer 69

the skills learned through social learning from the population’s
pool of learned skills, and the skills acquired through innovation from its own
asocial (individual)-learning ability (what one learns alone)

when cultural feedback is added, selection on an increased set of learned skills is achieved by improved social learning.
Owing to the high cognitive overlap, social learning improves the asocial (individual)-learning ability (i.e. intelligence).
More learned skills also improve the latter through stronger
experience effects

Question 70

Which orangutan species is more sociable

Answer 70

In the wild, Sumatran orang-utans are more social than Bornean orang-utans

Question 71

In the wild, Sumatran orang-utans are more social than Bornean orang-utans. How does this relate to cognition?

Answer 71

Various cognitive skills have been measured, such as innate problem solving, inhibition and exploration style. Sumatran sociable orang-utan show a superior problem-solving ability than less sociable Bornean orang-utans, inhibition is stronger in the more sociable species, and Sumatran orang-utans exploration style is more cautious, while Bornean orang-utans are more rough in their exploration style. Here, it was concluded that there was a stronger selection on cognitive mechanisms underlaying learning in themore social species, confirming predictions from the cultural intelligence hypothesis

Question 72

What is the general intelligence hypothesis

Answer 72

there had been coevolution of social, ecological and technical skills in primates, including cultural elements.

Question 73

why is social learning important ontogeny

Answer 73

. Social learning is a particularly
efficient mechanism of ontogenetic canalization (channelling during development), particularly in
large-brained animals

Question 74

Give 5 modes of primate communication

Answer 74

Olfactory communication
Tactile communication
Vocal communication
Visual communication
Multi-modal communication

Question 75

What are the 3 main elements of any type of communication

Answer 75

a 1) sender emits a 2)signal which is aimed toward a 3) receiver

Question 76

What are signals

Answer 76

messages that help coordinating behaviour in the interest of both sender and receiver

Question 77

What do signals in animals give information on

Answer 77

dominance status, phenotypic quality, reproductive status, group-coordination such as contact calls, and anti-predation such as alarm calls

Question 78

What are the 4 components of communication

Answer 78

signals
motivation
meaning
function

Question 79

What is the motivation component of communication

Answer 79

the internal state of the actor sending the signal, such as fear, aggression, sexual interest, appeasement

Question 80

What is the function component of communication

Answer 80

he adaptive advantage of communication, such as:
kin recognition, predator detection, competitor avoidance, friendship formation, mate attraction,
etc…

Question 81

What is the handicap principle

Answer 81

signals which are not costly cannot evolve

Question 82

Compare costly and non-costly signals

Answer 82

non-costly signals are hard to decipher and to predict, their outcome is uncertain rendering difficult to be selected;

costly signals (honest or deceptive) convey a selectable function, such as attracting mates or surviving from predators)

Question 83

What are the different types of costly signal

Answer 83

honest: Sender and receiver have common interests

incompletely honest: Sender and receiver have conflictual interests but share some common ground interests

Deceptive: Sender and receiver have conflictual interests
→ Receiver of deceptive signal must incur a cost

Carazo & Font, 2014

Question 84

Give an example of a deceptive signal in spiders

Answer 84

Salticid spider: males of a given species deceive females of another species by mimicking courtship tactile signals → attract these decieved females → catch and eat them

Question 85

How does the deception involved in deceptive signal remain evolutionarily stable

Answer 85

Most of deceptive signals are found in predator-prey interactions where deception is stable because the frequency of dishonest signals is low, so it can evolutionary be maintained because it is hard to be detected and to be counteracted by counterstrategies, due to its low frequency.

Question 86

Why , in non-human primates, are deceptive signals rare

Answer 86

constraints on false

signalling. These constraints include recognition, habituation, and punishment

Question 87

Describe recognition as a constraint on false signalling

Answer 87

regular interactions and individual recognition limit the use of deceptive tactics and false signalling

Question 88

Describe habituation as a constraint on false signalling

Answer 88

individuals rapidly learn to ignore false signals, progressively diminishing the effectiveness of deception; other constraint

Question 89

Describe punishment as a constraint on false signalling

Answer 89

detailed knowledge about social environment facilitates detection of dishonest individuals. If punishment follows detection, it reduces and negates benefits of acting deceptively.

Question 90

Is there any deception in non-human primates

Answer 90

subtle deceptive behaviour such as social tools and concealment of information are more difficult to detect so they can evolve

Question 91

Describe social tools as subtle deception

Give an example

Answer 91

Social tools consist of deceiving an individual, using that individual as a tool:

for example, in baboons, it has been observed that a
juvenile screamed at an older individual who was in possession of a valued food item. Such screams are normally only uttered by an individual when attacked or threatened. As a result of the scream, the youngster’s mother chased off her son’s ‘assailant’, while the youngster was left to take the relinquished food.

Question 92

Give some examples of colourful displays in primates

What does this reflect

Answer 92

in males, ornaments and colour display, such as the lip uncovering behaviour and red chest triangle in male gelada baboons, or the muzzle colour patterns in drill monkeys, or the colour patterns of some langurs, or the red lips of male sub-nosed monkeys. In these cases, visual display and colour ornaments indicate male quality, resource holding potential and dominance status of these individuals.

Question 93

Give an example of a vocal costly signal in apes

Answer 93

in orang-utans, Boris, the dominant male in this population, shows higher loud call rates than
subordinates males, in the middle and on the left. Orang-utan’s loud calls are assumed to constitute
honest signals of body male quality (mainly body size).

Fitch & Hauser, 1995

Question 94

Give a loud costly signal in gorillas

Answer 94

chest beats
larger males have a lower peak frequency of chest beat, meaning that larger males produce louder and deeper sounds when beating up their chest than smaller males. In this case, it suggests that chest beats are honest signals of body male competitive ability

Wright et al., 2021

Question 95

What are the vocal costly signals for female primates

When do these happen

What do they sound like

Answer 95

copulation calls

Females produce copulation calls during the copulatory act, but they also sometimes continue after the copulation in many primate species

Copulation calls can be grunts as in baboons or screams as in chimpanzees.

Question 96

Give 2 hypotheses to explain female copulation calls as costly signals

Answer 96

→ Honest signals to advertise reproductive status (Aich et al., 1990)

→ Encourage mate guarding by the consort male (Maestripieri & Roney, 2005)

there are >15
eg nonadaptive by-product of sexual intercourse, the self-stimulation of the occurrence of ovulation, the promotion of synchronization of male and female orgasm, strengthening the pair bond

Question 97

Give reasons why Roney (2005) may be correct in their hypothesis on female copulatory calls

Answer 97

→ Minimize sperm competition
→ post-copulatory sexual selection
→ Consistent with honest signals of fertility
→ Explains post-copulatory calls

Question 98

Give examples of olfactory costly signals

Answer 98

in lemurs, where female dominate the males, females use scent marking.
These species are seasonal breeders, so there is a strong female-female sexual competition during this period.
individual heterozygosity correlates positively with diversity of olfactory compounds
ince the odour-genes relationship
predicts health and survival during breeding season, it is suggested that scent marking acts as honest
olfactory ornaments of genetic quality.

Think of sweaty t-shirt study in humans (Wedekind, 1995)

Question 99

Which social systems are exaggerated sexual swellings associated with

Answer 99

multi-male multi-female social systems

All multimale social systems correspond to species where exaggerated sexual swellings are displayed (Nunn, 1999)

Question 100

What are female exaggerated sexual swellings associated with

Answer 100

patterns that bias paternity, such as ovulation taking place close to the peak of
swelling, and dominant males’ reproductive success

However, swellings are also associated with patterns that confuse paternity, such as errors in timing of ovulation

Question 101

What are the 6 hypotheses to explain exaggerated sexual swellings

Answer 101

Best-male hypothesis
- Clutton-Brock & Harvey, 1976

Reliable-quality indicator hypothesis (Pagel, 1994)

Obvious-ovulation hypothesis (Hamilton, 1984)

Many-service hypothesis (Van Noordwijk, 1985)

Many-male hypothesis (Hrdy, 1981; Hrdy & Whiten, 1987)

Graded signal

Question 102

What is the idea behind the best male hypothesis

Answer 102

swellings serve to incite male-male competition, enabling females to
identify and mate with best phenotype males. Here, there is indirect mate choice by the females,
and paternity certainty is increased

Question 103

Evaluate support for the best male hypothesis

Answer 103

not compatible with patterns of paternity confusion,

not compatible with non-matching of ovulation with peak of swellings,

not compatible with low-rank males siring,

does not explain gradual increase and decrease in size;

male-male competition does not require females to expose their fertility; weak support

Question 104

Describe the reliable quality indicator hypothesis

Answer 104

swellings reliably indicate female quality and so swellings evolve under the selective pressure of female-female sexual competition

Question 105

Evaluate the reliable indicator hypothesis

Answer 105

not compatible with largest swellings in least fertile females like adolescents,

not compatible with male-biased sex-ratio in multi-male multi-female groups, where female-female
competition is the lowest;

predicts larger swellings when breeding is seasonal but opposite is true
(largest in non-seasonal species).

Question 106

Describe the obvious ovulation hypothesis

evaluate

Answer 106

swellings indicate the timing of ovulation, hereby
increasing paternity certainty and thought to be an incentive for paternal care

incompatible with patterns that confuse paternity (synchrony of swellings and lowranking males siring), and male care not observed apart from possible infant protection.

Question 107

Describe the Many-service hypothesis

Answer 107

swellings help in promoting mate-guarding and courtship
and where females select the best male for protection against other males, predators and
neighbouring groups. In this case, paternity certainty is increased.

Question 108

Evaluate the many service hypothesis

Answer 108

compatible with unprecise signals of fertility (since what matters are other benefits than giving paternity to a particular male), compatible with unprecise timing of ovulation around the peak, as it tends to increase length of male protection and consortship, but it is not compatible with low-ranking males siring offspring

Question 109

Describe the many males hypothesis

Answer 109

swellings serve to attract many males as mating partners. Here, there is confusion of paternity, reduction of risks of infanticide, and even involves female cryptic choice (differential selection of gametes)

Question 110

Evaluate the many males hypothesis

Answer 110

not compatible with patterns that increase paternity, cannot explain why ancestry small signal would become exaggerated and why a large signal is needed. In fact, a large signal is not always needed as, in some multi-male primates, mating are incited even without swellings like in patas monkeys, vervets and red-tailed monkeys; also, confusion of paternity can be done by concealing ovulation or by not matching ovulation with maximum swelling peak

Question 111

Describe the graded signal hypothesis

Answer 111

exaggerated sexual swellings are indicators of the probability of ovulation, but not of its certainty

Nunn, 1999

Question 112

evaluate the graded signal hypothesis

Answer 112

compatible with both paternity certainty and confusion, and it explains the exaggerated aspect, since a gradual signal requires a period of growth and a period of decrease. In this case, dominant males mate-guard close to the peak and females mate with subordinate males outside of
the peak, explaining both dominant male reproductive skew but also why subordinate males can sire offspring.
Since it is just a probability, dominant males have more chances to sire than subordinates, but subordinates still have a chance to sire

Question 113

Where does the idea of swellings as an honest signal of female fertility and female quality come from

is it accurate

Is this true or all primates

Answer 113

baboons, where swelling size is associated with the probability of ovulation

Most of swellings measurements correlate with female fitness-related variables (Domb & Pagel, 2001)

no eg : In chimpanzees the graded-signal seems to apply.

Question 114

Describe how the graded signal applies to chimps

Answer 114

Swelling size increases as the ovulation approaches, but swellings remain large even after ovulation.

male’s copulations concentrate around the period of maximum swellings.

even within the traditionally defined maximum swelling period, further slight increases in swelling size indicate approaching ovulation, and male mating interest changes according to the changes in swelling size.

absolute swelling size during the periovulatory period increases and the alpha male associates more with females as the number of cycles to conception decreases.

when having the choice between several ‘‘maximally’’ tumescent females, the alpha male prefers the female that is in the fertile phase of her cycle rather than those with the biggest swelling at that time.

Question 115

How does female chimp ovulation differ with swelling size

Answer 115

probability of ovulation and swelling size are correlated.

However, although ovulation is virtually restricted to the second half of the period of maximum tumescence, its timing varies considerably in relation to both the onset and the end of the maximum tumescence phase.

Probability of ovulation, however, is not random, but peaked on day 7 after the onset of the maximum swelling phase and is almost 60% between days 7 and 9.

Thus, in wild chimpanzees, perineal swelling indicates the probability of ovulation, but does not provide sufficient information to deduce its exact timing

Question 116

True or false

In gibbons, exaggerated sexual swellings are explained by the graded-signal

Answer 116

true
Barelli et al., 2007
found the probability of ovulation peaked on day 3 of the maximum swelling period. Nevertheless, the temporal relationship between maximum swelling and probability of ovulation varied from day − 1 to day 13 of the swelling period and three times ovulations fell outside the maximum swelling phase.

Question 117

How reliable are signals in bonobos

Answer 117

swellings are a very unreliable signal of female probability of ovulation

Question 118

What makes bonobo sexual swellings a very unreliable signal of female probability of ovulation?

Answer 118

duration of cycle is extremely variable and the ovulation does not coincide with the peak of swellings

The suggested function of swellings in bonobos is that they serve in decreasing mate-guarding due to their variable length where males have to move from one female to the next without having a clue of their ovulation, they decrease paternity certainty and increase female choice.

Douglas et al., 2016

Question 119

In which type of primates is olfactory communication mostly used

what is it usually used to communicate

Answer 119

Prosimians

Indicate dominance status, genetic quality

(s also common in new
-world monkeys, particularly in Callitrichids, but for different function?)

Question 120

What is the hypothesised function of olfactory communication in NWMs

Answer 120

scent marking was used in territoriality

regulation of social and reproductive dominance

scent marking acts in mating competition and intersexual mate choice.

Question 121

Why is the territoriality hypothesis about the function of olfactory communication in NWMs not correct

Answer 121

there is not difference in scent marking behaviour between the centre of the territory and the periphery so it seems that scent marking does not act in territoriality.

Question 122

Why is the regulation hypothesis about the function of olfactory communication in NWMs not correct

Answer 122

Several elements do go in this direction, such as dominant individuals tend to scent mark more than subordinates, and in some species, reproductive suppression of subordinates via scent marking occurs. However, across species and populations, evidence remain scanty

Question 123

What is the support for scent markings in NWMs being part of mating competition and intersexual mate choice

Answer 123

t subordinates increase their scent marking during intergroup encounters (individual advertisement of quality – mate attraction), but also that increased scent marking during intergroup encounters by dominant is observed (deter females immigrants – intrasexual competition). Also, species where paternal care is superior to maternal care, female scent mark more than males (intersexual competition – females tend to attract the best father).

Question 124

What does grooming function to do (4)

What are 2 other forms of tactile communication? What are the role of these?

Answer 124

→ reconciliation
→ consolation
→ bonding
→ mother-infant interactions (bonding, protection, maternal care)

Touching other‘s (shoulder, loins, root of tail, testes)
→ reassurance
→ bonding reinforcement

• Embracing, lip contact, greetings ceremonies
  → reassurance
  → bonding reinforcement

Question 125

How common is vocal communication in primates

Answer 125

ubiquitous

Question 126

Give 7 roles of vocal communication in primates

Answer 126

• Emotional expression (screams)
• Dominance status (grunt – baboons, chimpanzees)
• Individual identity (pant hoots – chimpanzees)
• Territorial advertisment (loud calls– howler monkeys, orang-utans, gibbons)
• Sexual advertisment (copulation calls)
• Social bonding (coordinated chorus–
  chimpanzees, gibbons)
• Functional reference (alarm calls)

Question 127

How do the alarm calls of vervet monkeys constitute a semantic communication?

Why is this interesting?

Give an example

Answer 127

each type of alarm call acts like words

This referential communication is thought to be a precursor for language evolution.

eg in vervet monkeys, for three different predators,
a leopard, an eagle or a snake, a different alarm call is emitted. In addition, behavioural responses to each of these calls differ: for an eagle, individuals hide in a bush; for a leopard, they climb a tree; and for a snake, they stand up.

Question 128

Describe the functional alarm calls of Diana monkeys

Answer 128

Zuberbuhler, 2000

Spectrogram of male alarm calls for a leopard, and spectrogram for an eagle (bottom). They clearly differ and show a different call structure for different predators. In addition, calling rates differ depending on the distance of the predator (illustrative figure) and differ depending on the location of the predator (bottom of the figure). Not only these primates have different words for different predators, but they also can convey a whole series of complementary information about the location of the predator.

Question 129

Do primates have different facial expressions

Answer 129

In primates, facial expressions display a high flexibility and mostly express emotions. In primates, the position of the lips, the orientation of the eyebrows and the mouth are particularly important.

Question 130

Use an example to show how primates use facial expressions

Answer 130

in Barbary macaques, different facial expressions correspond to various emotional states, such as aggressivity, with open mouth and showing teeth, or threat with open mouth and teeth covered and wide-open eyes, or distress with yawning and canine display, or submission, showing teeth and grinning but with closed mouth, or friendly and neutral expressions

Question 131

Which visual communication is particularly important for sympatric guenons

How do we know this

Answer 131

facial colouration

use patterns of colours on the face to recognize each species

an experiment, involving machine learning, revealed that facial traits are critical for accurate classification and facial traits influence selective attention toward conspecific and heterospecific faces. Also, guenon species show a high variability in reliance on single-trait or whole facial characteristics

Question 132

What is an important advantage of gestures over vocalisation

Answer 132

more flexible

Question 133

Why might gestures be precursors to human speach

Answer 133

in humans, gestures appear in infants before spoken language, which gives insights on gestures being also precursors of human language.

Question 134

Describe gestures in bonobos and chimps

Answer 134

flexible
For example, a chimpanzee claims some food by stretching his arm, and a bonobo displays a sexual invitation by lifting his arms. In chimpanzees and bonobos, facial, vocal and gestures are emitted on a regular basis, but gestures are less tied to contexts than vocalizations and facial expressions: the correlation across contexts for gestures is much lower than for vocal and facial signals, showing this high flexibility in gesture usage

Question 135

How do we know primate gestures are intentional

Answer 135

in orang-utans, about 40
gestures have been observed, used in various contexts and used to achieve 6 social goals: to initiate
an affiliative interaction (contact, grooming, or play), to request objects, to share objects, to instigate co-locomotion, to cause the partner to move back, or to stop an action. Intentionality here is shown since, when actions of the recipient did not match gestures‘ meaning, gestures were repeated over and over and even changed until the goal was reached. Also, orang-utans modify their gestural signalling according to their audience comprehension.
Cartmill & Byrne, 2010

Question 136

Give an example of apes changing gesturing behaviour because the audience was not understanding

Answer 136

Orangutans’ (from both Sumatra and Borneo) behaviour varied according to how well they had apparently been understood. When their aims were not met, they persisted in communicative attempts. However, when the interlocutor appeared partially to understand their meaning, orangutans narrowed down their range of signals, focusing on gestures already used and repeating them frequently. In contrast, when completely misunderstood, orangutans elaborated their range of gestures, avoiding repetition of failed signals

Cartmill & Byrne, 2007

Question 137

Give example of how Gestures in apes can flexibly be adjusted to social circumstances

Answer 137

In juvenile wild chimpanzees, play solicitation gestures were studied, and researchers found that audible and visual gestures increased with infant age, and that tactile gestures differed between the sexes, also that audible and visual gestures were higher in interactions with conspecifics than with mothers, and finally that
object-associated and self-handicapping gestures were frequently used to initiate play with same aged and younger play partners, respectively. So, gestures in young chimpanzees are quite diverse, vary over time and are used differently by males and females and depending on the audience. Here gain showing a high flexibility.

Froehlich et al, 2016

Question 138

What is multimodal communication

Answer 138

combination of vocalization, gestures and facial expressions

Question 139

What are the 3 key functions of multimodal communication in primates

Answer 139

content-based
efficacy-based
inter-signal interaction

Question 140

Describe the content based function of multimodal communication

Answer 140

addresses the factors affecting the message or information of the signal (the „why“ of signal) and in which we can find redundancy where different components of multi-modal signal convey the same information or complementarity where different information is conveyed in each channel

Question 141

Describe the efficacy based function of multimodal communication

Answer 141

addresses how effectively a signal is received and processed (the „how“ of signal) and in which each signal component acts as a backup to the other in presence of environmental noise. Here, multi-modal communication is based on imperfect information coding from the recipient, and it increases the probability of a receiver response across a variety of environmental conditions

Question 142

Describe the intersignal interaction function of multimodal communication

Answer 142

where several signals are used as refinement of information, for disambiguation of a situation.

Question 143

What did Hobaiter et al., 2017 show about multimodal communication

Answer 143

wild chimps do use combinations of Gestures + vocalizations

wild chimpanzees, after perceived goals were not achieved, switched to gesture–vocalization combinations only if the initially single signals were vocal.

gesture and vocalization in these cases conveyed partly different information, with gesture serving to resolve ambiguity in signal meaning. This also supports the hypothesis that many signal combinations in great apes are non-redundant, but also non-complementary.

Question 144

Give the animal behaviour definition of culture

Give a humanities definition

Answer 144

behavioural practice that is shared among members of a group; is performed repeatedly over a period of time (that is, it is enduring); and depends to a measurable degree on social contributions to individual learning for its appearance in new
practitioners

Fragazy, 2003

shared patterns of behaviours and interactions, cognitive constructs and understanding that are learned by socialization. Thus, it can be seen as the growth of a group identity fostered by social patterns unique to the group.

Question 145

What are common elements found across many definitions of culture

Answer 145

common behaviour among group members

social transmission

Question 146

What do Laland and Hoppit (2013) consider to be the difference between cultural traits

Answer 146

traditions are cultural traits

Question 147

How did McGrew 2004 consider tradition

Answer 147

Behaviours that are practiced habitually in a group, rely in maintenance and
transmission on social learning
“the way to do things” McGrew, 2004

Question 148

How do animal behaviourists define tradition

Answer 148

all group-typical behaviour patterns, shared by members of animal communities,
are to some degree reliant on socially learned and transmitted information

Question 149

Why may we think animal culture requires technology

Answer 149

When we hear about animal cultures, we often associate them with technology, such as tool use

Chimpanzee nut cracking, stick tools in birds or macaques opening shells with stones are straightforward elements that can classified as cultural elements, since they require learning and social transmission

Question 150

Give 3 examples of how animals can have culture outside of technology

Answer 150

Social-sexual→ greetings, gestures…
Communication→ Associative vocalisations, dialects…
Feeding → Feeding preferences, hunting techniques

Question 151

How can we study culture in animals

Answer 151

Method of exclusion
comparing neighbouring groups or communities within the same field site
socially learned skills counting
3 factor model

Question 152

How does the method of exclusion work when studying animal cultures

Answer 152

consists of comparing field sites, listing all the observed behaviours. We then exclude all behaviours of which the presence or absence in given places can be explained by genetic differences, and we exclude those of which the presence or absence in given
places can be explained by ecological differences, and we also exclude behaviours that are found everywhere. In brief, when a behaviour is done everywhere, it doesn’t not correspond to a cultural trait, and when a behaviour presence somewhere but absent somewhere else cannot be explained by genetics or ecology, these traits are considered as cultural.

Question 153

Give an example of how the method of exclusion has been used to explore primate culture

Answer 153

used to study wild chimps in 6 field sites and found 39 cultural traits, some of which were not tech based eg hand clasp

Question 154

Give an example of how different chimp cultures mean similar gestures mean different things

Answer 154

in the Gombe chimpanzees, an invitation to copulate by a male is done by clipping leaves, while this behaviour is done in the Taï chimpanzees before drumming. A copulation invitation in Taï is done by knocking the heel on the ground

Question 155

What did van Schaik (2002) find when applying the method of exclusion to populations of orangutans including Sumatra and Borneo orangutans (4)

Answer 155

24 cultural variants in areas such as social and feeding

Cultural variation increases
with geographic distance

Size of cultural repertoire associated with opportunities for cultural learning

social learning opportunities increase the number of cultural variants.

Question 156

What did Santorelli et al, 2011 fine when studying spider monkey culture using the method of exclusion

Answer 156

22 variants
57% in social domain
19% in food-related domain
24% in others domains

Question 157

In white-faced capuchins, the method of exclusion has been applied to foraging traditions. What did they find

Answer 157

Within the same country, in Costa Rica, four populations have been compared. It was found that 20
food items were processed differently across sites

Army ants are ants that make very long processions from nest site to nest site. One population of capuchins has been observed following the trail of the ants to find the nest and to feed on the larvae, while the other populations
have not been observed doing this behaviour.

Question 158

Give 5 conceptual issues with the method of exclusion

Answer 158

Ecological pressures drive adaptive behaviour which can also be cultural

Genetics influence animal’s predisposition for social learning

Animals modify their environment, also via culture (niche construction)

Universal behaviour can also be cultural (e.g. nest-building)

Distant populations: cannot rule out influence of genetic and ecology

Question 159

How was the comparing neighbouring populations method used to investigate chimp culture

Answer 159

s used to study chimpanzee cultural variants, particularly nut cracking behaviour in the Taï chimpanzees. Nut cracking is done by either using a stone hammer, or by using a wooden hammer - methods can be compared between the 3 groups here (North, South and East)

East group uses continuously stone hammers throughout the season
both South and North groups decrease over time using stones as hammers to crack nuts

stone tool use habits vary between neighbouring communities, which then can be qualified as traditions.

Question 160

How does wooden tool use compare bewteen the 3 populations of chimp in Tai

Answer 160

the three groups increase the proportion of wooden hammer used across the season, but at very different rhythms

different traditions

Question 161

Describe the how the traditions of the 3 chimp groups vary across time

Answer 161

Luncz & Boesch, 2014, compared from 1983 to 1989 and from 2008 to
2013

Throughout the season, for both stones and wooden hammers, habits are conserved
across time

Traditions perpetuate through generations and remain

Question 162

What is conformity

Answer 162

Conformity occurs when all members of the same group behave similarly and is characterized by the fact that newcomers follow the habits of their new group

Question 163

Give evidence for conformity in chimps

Answer 163

Luncz & Boesch, 2014, recorded the tool use of a new female chimp over the first 55 weeks after her arrival

new female increases progressively her stone tool use to eventually follow the same pattern than individuals of her new group. In other words, this new immigrant conforms to her new group’s tradition.

Question 164

Is ant dipping tool length constant

Answer 164

no
Ant-dipping tool length varies widely across chimpanzee study sites, across type of army ants and across dipping locations in the Kalinzu forest

Question 165

Ant-dipping tool length varies widely across chimpanzee study sites, across type of army ants and across dipping locations in the Kalinzu forest. is this due to ecology or culture

Answer 165

ant-dipping tool length varies within the same population between two neighbouring communities, here reflecting again a cultural variant within this population of chimpanzees.

Question 166

What benefits does the Counting socially learned skills approach bestow (3)

What have we learnt from this approach (2)

Answer 166

→ Increase the general cultural repertoire
→ Modify distribution of variants across behavioural domains
→ Reveal ecological correlates for most of cultural elements

culture is pervasive and widespread,
and that culture drives local adaptations.

Question 167

When comparing orangutan culture, how does using method of exclusion and socially learned skills methods compare

Answer 167

First, the number of cultural behaviours displayed by the sociable Sumatran orang-utans is higher than what is seen in Borneo.

Second, when using the socially learned skills method, the number of cultural behaviours increases in both populations.

Question 168

What kind of cultural traits does the method of exclusion find

Answer 168

socially learned behaviours with a patchy geographic distribution but without ecological correlates (mostly conspicuous and/or high complexity behaviours such as tool use)

Question 169

What are cultural behaviours with ecological correlates

Answer 169

socially learned behaviours that vary between populations because they are influenced by a population’s local ecology (e.g. feeding skills).

Question 170

What are cultural universals

Answer 170

socially learned behaviours and knowledge that we find consistently across populations (e.g. basic subsistence and social skills).

The sum of all socially learned behaviours
represents an individual’s cultural knowledge

Question 171

What does the 3 factor model of studying primate culture consider

what does it assume

Answer 171

the co-influence of environment, sociality and cognition on the emergence of cultural behaviours

environmental opportunity, rather than necessity is the main driver of material culture.

Question 172

What did Koops 2014 show regarding opportunity vs necessity in primate culture

Answer 172

In insectivores, ant dipping increases when more ants available and nut cracking increases when more nut trees available
→ Opportunity supported

Ant dipping increases when more food available and nut cracking decreases
when more food available (dry season: more food)
→ Necessity not supported

Question 173

Give the reasoning behind the 3 factor model

Answer 173

environment, sociality and cognition influence the propensity to invent and innovate, they influence the capacity to transmit information and innovation and the capacity to fixate a behavioural trait in the population. In addition, environment influence cognitive and sociality abilities

Question 174

What is asocial learning

How is this usually done

Answer 174

where individuals acquire information/skills without other‘s influence.

This way to learn is often done by trial-error, which takes time.

Question 175

What is social learning

Answer 175

influenced by the observation of, or interaction with, another individual or its products. It is a much faster process than asocial learning

Question 176

How can social learning be done

Answer 176

simple imitation, where one copies the behaviour of the role model, without real inference on the goals;

emulation, where one individual imitates the actions of a model in order to achieve the same goal; we also can learn from others by

facilitation, where the level of effort is increased as a result of the presence of others;

teaching can help in learning from others, where the model actively modifies the actions of the individual to improve its efficiency.

Question 177

When does an innovation become a tradition

What is required for this occur

what is the path to get
fixated, transmission through social learning is required

Answer 177

An innovation becomes cultural (tradition) when it gets fixated within a population

To get fixated, transmission through social learning is required

an innovation emerges, this innovation is copied by other individuals, and then transmitted to the next generation by social learning until all individuals in a population perform the same behaviour, where it then becomes a tradition.

Question 178

In which directions can social transmissions be

Answer 178

horizontal
vertical
oblique

Question 179

Give an example of an innovation that did NOT become a tradition

Why though

Answer 179

dental flossing in Japanese macaques

group was too big, or the fact she had only two kin members in the group, or that she was lowranking, or even that this innovation is not very useful neither functional.

Question 180

Describe what happened with dental flossing in Japanese macaques

Answer 180

In a group of Japanese macaques, a spontaneous innovation emerged, performed by only one individual, who was using the fur of other individuals, or her own fur, to remove pieces of food between her teeth, as one would do when we floss our teeth. She used variable techniques (pictures). However, after years of practice, she remained the only individual in her large group to do this behaviour. The innovation did not spread in the group neither in the next generation.

Question 181

Give an example of an innovation that did take hold in Japanese macaques

Answer 181

sweet potatoes washing

wheat placer mining

Question 182

Describe the story of sweet potato washing and wheat placer mining in Japanese macaques

Answer 182

In 1953, only one individual innovated by washing sweet potatoes that villagers gave to this isolated population on a small island during the winter.

Ino, this female macaque, started to wash the potatoes in the sea to remove the grains of sand.

Another behaviour was
innovated by the same individual: washing wheat. She separated the grains of wheat from the sand by throwing them into water, and she started doing that in 1956.

In a few years, these behaviours were transmitted to her offspring and to the rest of the troop. Very good examples of
vertical transmission and of a new culture emergence.

Question 183

What is the idea behind tool use being the driver for the evolution of language

Answer 183

stone tool use
is socially transmitted, and that using tools leads to the co-evolution of teaching and language in order to improve the efficiency of using, modifying and making tools. In other words, by developing language, individuals are better of explaining, and so teaching how to make tools, and also they are able to improve the efficiency of tool making.

Question 184

What did Morgan (2015) do to evidence the co-evolution of tool use and language

Answer 184

experimental reconstructions of stone tool manufacture, using either imitation, or emulation (looking at result of tool making in presence of someone else without interaction), basic teaching (in presence of an experienced tool maker, where tutors could manually shape the pupil’s grasp of their hammerstone or core, slow their own actions and reorient themselves to allow the pupil a clear view - this condition replicates teaching reported in non-human primates), or gestural teaching where tutors and pupils could also interact using any gestures, but no vocalizations, or verbal teaching where tutors and pupils were also permitted to speak, it was shown that the best performance was obtained using active teaching through language

All parameters associated with efficiency in stone tool manufacture where better when the actions were actively taught using language, as compared to simple imitation, emulation, basic teaching or gestural teaching.

Question 185

How is the idea of co-evolution of tool use and language is also apparent in brain structure

Answer 185

the parietal cortex is involved in tool use, language and motor control

PF area, the PGI area and the AIP area.
Each of these areas strongly overlap in what they control, and they correlate with tool use, language, motor control, sensory system and executive function.

Similarity of cognitive processes and cortical networks involved in speech and tool use

Question 186

Give an example of the similarity of cognitive processes and cortical networks involved in speech
and tool use

Answer 186

Darwin (1872) noted that when cutting something with a pair of scissors we often unconsciously clench and unclench our jaws, as if to sympathetically mimic the hand movements;

in our scheme this would be an example of synkinaesia between the motor maps for the mouth and hand, which are right next to each other in the Penfield motor homunculus of the pre-central gyrus

(Ramachandran, 2001)

Question 187

What are 3 evolutionary scenarios for the emergence of language with tool use

Answer 187

In (a), the
emergence of language produces the shift from the Oldowan to the Acheulean.

In (b), technical reasoning skills are sufficient for the Acheulean because the combinatorial capacities are
compensated by feedbacks occurring through the progression of the task. Later, these combinatorial capacities are internalized either by the emergence of language or by a kind of Baldwin effect (better fitness for great learners).

In (c), the combinatorial capacities of the frontal lobe/Broca’s area are
initially not language-related but are used for other purposes (e.g., sensorimotor systems). These capacities are reused later in recycling first technical-reasoning skills and then language skills

Question 188

What makes human culture unique

Answer 188

→ Cumulative culture
(we gradually improve techniques)
→ Ratchet effect
(we build on what our predecessors have invented
Innovations jump from one mind to the next, throughout the population)
→ Active teaching ? (chimpanzees might)
→ Language (written and spoken)
→ Strong power of normativity 

→ Cultural and biological evolution (dual inheritence)

Question 189

Give the stages of cumulative culture in human evolution

Answer 189

LCA (5-7My): wooden and stone tools, no modification

Early Homo (2.5-0.2My): simple stone tools, modification

Homo sapiens (0.2My): cumulative culture, elaborated modified tools (stone, wood, bones,…)

Question 190

Give 3 scenarios for the evolution of cumulative culture

Answer 190

foraging niche
breeding system
tool use

Question 191

How could the human foraging niche have led to the evolution of cumulative culture

Answer 191

new foraging niches, like scavenging, hunting and gathering allowed for more sociality. More sociality led to more opportunities for social learning, division of labour, which resulted in richer cultural repertoire and specialization in tasks.

Question 192

How could the human breeding system have led to the evolution of cumulative culture

Answer 192

a new breeding system with pair-bonding, provisioning of mothers and children increased the motivation to share information. This led to the development of active teaching, as seen in other animals where cooperative breeders show some teaching while individual breeders don’t. Eg, in meerkats, adults actively teach young pups pre-handling skills of preys. Cooperative breeding also involves share intentionality with other group members, and thus the emergence of language linked to teaching as we have seen earlier

Question 193

How could the human tool use have led to the evolution of cumulative culture

Answer 193

more and more complex stone tools required better learning abilities and where the Baldwin effect took place, with individuals with better learning abilities had greater fitness and could expand culture. A feedback effect took place, with the dual inheritance where cultural niche construction (meaning the modification of environment to reduce selective pressures) accelerates in turn culture-gene coevolution

Question 194

What is the Baldwin effect

Answer 194

an organism’s ability to learn new behaviours (e.g. to acclimatise to a new stressor) will affect its reproductive success and will therefore have an effect on the genetic makeup of its species through natural selection.

Question 195

What are primate communities

Give an example

Answer 195

when several primate species are sympatric

eg Lopé National Park, in Gabon which includes Western lowland gorillas, central chimpanzees, black colobus, grey-cheeked mangabeys, putty-nosed monkeys and many more which occupy different forest strata and have variable body size

Question 196

How do primates in communities cope with being sympatric

Answer 196

niche partitioning

Question 197

Exemplify niche partitioning in the primate community in Brazil

Answer 197

each species occupies different strata in the forest, their diet diverges from the others, and they vary also in body size, reducing the competition.

For example, a species of spider monkeys lives high in the canopy and mostly eats leaves, while another species of spider monkeys,
also living in the canopy, eats mostly fruits.
Squirrel monkeys
occupy the lower strata of the forest, as
do capuchins, but squirrel monkeys mostly eat insects while capuchins are omnivores and have a
diverse diet.

Question 198

Describe niche partitioning in Gabon

Answer 198

partition among terrestrial primates (chimps and gorillas)

isotope sampling shows the different species eat different foods with a small overlap, where there will be competition
(Oelze et al., 2014)

Question 199

Why is ecological change particularly dangerous for primate communities

Answer 199

feeding competition results in a limited total biomass of primates, where each species is represented by a small number of groups and individuals.

Niche partitioning allows primates to live among other species, but there is still a certain degree of competition, rendering these communities fragile when any change in the environment and the ecosystem occurs.

Question 200

How many primates eat different foods in Gabon

Answer 200

a small percentage of food items is eaten by all 8 species, but also about half of food items are eaten only by one species

Question 201

What are 3 benefits of inter-specific associations

Answer 201

habitat use

anti-predation

foraging efficiency

Question 202

What is the primary driver of inter-specific associations

Answer 202

anti-predation - benefits from alarm calls and vigilance of others – primary driver of polyspecific
associations

Question 203

How does inter-specific association affect habitat use

Answer 203

individuals occupy strata they wouldn’t occupy otherwise

→eg Colobus going to the ground for geophagy during inter-specific associations

Question 204

How does inter-specififc association affect foraging

Answer 204

improves efficiency
individuals/species on the ground feed on food dropped by other primates, profit of others’ knowledge on food location and food depletion

Question 205

Costs due

to polyspecific associations are ..?

Answer 205

feeding competition
interbreeding
parasitism (if one doesnt benefit)

Question 206

Give an example of the mutual anti-predation benefits of polyspecific associations in Tai forest

Answer 206

Diana monkeys and red colobus association

Diana monkeys: primary alarm callers; were more exposed during associations (expected if risk of being caught by an eagle is reduced when in association)

Red Colobus: use lower strata more often, more exposed to forest floor, look down less often when foraging, come down to feed on termite hills
→ Reduce predation pressure when in association

also, predation benefits involve dilution and confusion effects when group size increases

Bshary & Noë, 1997

Question 207

Give an example of the mutual anti-predation benefits of polyspecific associations in Kibale National Park, in Uganda.

Answer 207

redtail monkeys associating with blue monkeys

both species reduce their vigilance behaviour when in association
→ Reduce predation pressure when in association

Question 208

Give an example of the habitat use changes of polyspecific associations

Answer 208

Goeldi’s tamarins tend to increase the use of middle and lower canopy when they associate with saddle back tamarins and with white lipped tamarins. This change of strata usage seems associated with a change in diet. In fact, saddle back and white lipped tamarins have a better knowledge of food locations than Goeldi’s monkeys, and those ones increase the amounts of fruits eaten during the wet season, when in association as compared to when alone

Question 209

Give an example of parasitism in polyspecific associations

Answer 209

Goeldi’s monkeys, in association with with saddle back tamarins and with white lipped tamarins, increase their foraging efficiency, while no clear benefit is demonstrated for
the other species. This example can illustrate a form of parasitism by Goeldi’s monkeys, even if costs
for the two other species are not so clear

Question 210

Give an example of foraging efficiancy in polyspecific associations in guenons

Answer 210

Foraging efficiency also occurs for three species of guenons associating with each other in the Lopé National Park:
the crested mona monkeys,
the moustached monkeys
the putty-nosed monkeys

When they associate, they shift habitats, occupying areas with richer supply of food species. This makes their foraging effort more efficient, and it results in a more diverse diet. They also show anti-predation benefits, as a division of labour gets organised, with moustached monkeys,
who live lower in the canopy watch out and alarm call for terrestrial predators, while the two other species who occupy higher forest strata watch out and alarm for aerial predators

Question 211

How does foraging efficiency improve when Diana monkeys and red colobus

Answer 211

Diana monkeys increase slightly their quantity of arthropod preys in their diet, as compared to when they do not associate. Difference shown in the figure, even if statistically, in this study, the difference was not significant. Here, anti-predation remains the main benefits of association in this system.

Question 212

How can the benefits linked to predation, habitat use and foraging can work together

Answer 212

In the Taï forest, Diana monkeys and red colobus associate often with sooty mangabeys, who are the most efficient sentinels for terrestrial predators, given that they also are terrestrial.
Strata used by red colobus when associating with mangabeys as compared to when they
are alone: when they hang out with mangabeys, red colobus go much lower than when they are alone.

Same analysis for Diana monkeys reveals a similar pattern: Diana monkeys and red colobus descend to low forest levels and forest floor more often when in association with sooty mangabeys, which corresponds for them to a niche extension, which in turn provides foraging advantages, particularly for red colobus who can access to the ground and feed on termite hills.

now we see that by changing habitat use they also gain some forms of feeding benefits

Question 213

How do guenons avoid inbreeding

Answer 213

have evolved peculiar facial colouration patterns, enabling them to tease apart which species is which

Question 214

What is the Co-evolution principle

Answer 214

Reciprocal evolutionary changes between pairs of species or groups as they interact with one another

Question 215

What is the angiosperm coevolution hypothesis

Answer 215

our primate ancestors evolved key adaptations like forward-facing eyes, excellent colour vision, rounded, blunt teeth and fingers without claws, all for the purpose of eating and living from fruits

As angiosperms began to evolve into tropical forests, they became bigger and bigger and so did their seeds.
They needed large animals to spread these seeds…edible fruits developed as a means of attracting large animals for this dispersal… three types of animals co-evolved with these large tropical angiosperms:
frugivorous bats, frugivorous birds, and primates.

Sussman et al., 2012

Question 216

What is the Visual predation hypothesis

Answer 216

forward-facing eyes and grasping hands evolved in primates to allow them to eat insects in trees
Carmill, 1974

Question 217

Give an overview of how seed dispersal by primates functions

Answer 217

: first, primates have co-evolved with
plants, in particular to detect ripe fruits through olfaction at first and through vision. Primates eat
fruits with a fleshy pulp surrounding seeds. Primates disperse the seeds by handling the fruits, by
ingesting them and defecating them at some distance from the parent tree, and in turn tree locations
influence primate movements. After dispersal, the fate of the seeds depends on the location where
they were dropped, since many seeds tend not to survive under the parent tree, or they need areas
with more sunshine to grow, such as gaps created by fallen trees that primates like to use to rest and
groom. The consequences are that the tree community structure is strongly determined by this
dispersal, having consequences for the whole ecosystem.

Question 218

How does dispersal distance affect a seed’s likelihood of surviving

Answer 218

seeds just under the parent tree are less likely to survive, due to high parasite load, than those deposited further away

Question 219

Which primates sites are particularly important for seed dispersal

Answer 219

Primates sleeping sites are important areas where seeds get deposited.

Question 220

What do cercopithecines do with seeds

Answer 220

spit them out

Question 221

What part of cercopithecine anatomy increases seed dispersal distance

Answer 221

cheek pouches where they can store fruits, so it means that they process these fruits as they move, therefore dispersing seeds further from the parent tree after eating the flesh.

Question 222

What do chimps do with seeds

Answer 222

swallowed

They are then defecated much further form the parent tree. A lot of seeds need to go through the gut to be able to germinate.
Germination is favoured by the nutrients present in the faecal matter

Question 223

What type of fruits have OWMs and NWMs specialised to eat

Answer 223

pecialized in eating colourful fruits, with a fleshy pulp surrounding small sized seeds that can easily be swallowed.

Question 224

Which type of primate was found to have the most seeds in their dung

How many trees were able to disperse their seeds in primate dung

Answer 224

Gorillas and chimpanzees

up to 125 species of trees

Poulsen et al., 2001

Question 225

What happens to the seeds after defecation

Answer 225

60% of defecated seeds eaten by three species of new world monkeys germinated

of which: 50% were removed by secondary seed dispersers or killed by seed predators

Question 226

How does the fact seeds end up in dung help trees other than dispersal

Answer 226

Seeds defecated by tamarins in Peru

Secondary dispersal by dung beetles

35% of defecation visited by dung beetles
of which 24% were buried by dung beetles

burying improved chances of germination as compared to if they remain under the parent tree and remain on the ground floor

Question 227

Compare the seed handling of sympatric wild chimpanzees and Lhoest monkeys

Answer 227

chimps:
Defecate large seeds (>0.5cm)
Discard wadges
containing many seed
→ Defecated deposited farther from an adult conspecific
chimpanzees
→ Lower persistence but better establishment

Lhoest monkeys:
Spit single seeds
→ Orally-discarded deposited closer from an adult conspecific
→ greatest persistence but poorest establishment

Question 228

What kind of predator is the baboon

Answer 228

opportunistic predator

hunt on various species of antelopes, but also hares and birds

Question 229

What do capuchins hunt

Answer 229

birds, eggs, lizards, frogs, young coatis, bats, rodents

Question 230

Why have macaques been beneficial for palm oil farmers

Answer 230

macaques hunt on rats in palm oil plantations, contributing to a reduction of 10% of lost yield for the farmers and may constitute an interesting avenue of biological control over pesticides in this Malaysian palm oil plantations.

Question 231

Is primate predation always opportunistic

Answer 231

No

chimps plan predation with hunting tactics: cooperative action, shared goals and share intentionality

Question 232

Give an example of a chimp hunting strategy

Answer 232

individuals distribute roles, with a driver chasing the monkey they want to capture, other individuals block ways to escape in the canopy;
other individuals, on the way the monkey is using, chase the prey while other individuals wait at the end of the way to capture the prey - the ambushers.

All these roles are perfectly understood by all individuals, and all participants will then share the food

Question 233

Give an example of a hunting tactic used by chimps hunting a rabbit

Answer 233

some individuals are
chasers, while other individuals are blocking the route. These patterns reveal strong abilities to
understand the goals and intentions of others, as well as coordination and cooperation

Question 234

When do wild chimps hunt

Answer 234

most hunting events occur during the season when there is a lot of food, so not related to energetic needs (Mitani & Watts, 2001)

hunting rates are higher when more individuals are present in the group and when more males are present in the party

Question 235

Why may chimps hunt more when the group is bigger

Answer 235

More individuals mean more chances of success.

meat is shared and used to reinforce alliances, bonds and friendships.
Levels of oxytocin, related to social bonding - when no food sharing occurs, and when food sharing occurs, showing that sharing food increases this oxytocin level.

Question 236

What happens if chimps hunt sympatric monkeys

What is a consequence of this

Answer 236

decrease in monkey population
this happened with red colobus in Kibale National Park

as the population of red colobus decreases, the chimpanzees have to travel further and further to encounter them, and potentially to hunt them. It seems, in this chimpanzee population, that hunting red colobus is done in an unsustainable way, resulting in local depletion of red colobus.

Question 237

What kinds of parasites do primates host

Is this very detrimental to them

Answer 237

They can have macro-parasites, like external parasites such as ticks, but also a lot of internal ones like worms and bacteria. Primates are also hosting micro-parasites like viruses such as SIV, STL and Herpes

primates are asymptomatic carriers, where they don’t actually develop symptoms and don’t get sick but they can transmit these viruses and parasites to other individuals and animals in their environment. However, primates are also vulnerable to a lot of diseases, such as Ebola or anthrax.
They also can contract coronaviruses and even by leprosy.

Question 238

Why does parasite load vary across primate populations

Answer 238

First, one can see that parasites found in prosimians are less diverse than those found in the other primates, the apes having the highest parasite richness. Researchers have investigated what can explain this variation and body mass was proposed - larger primates having more parasites and a richer internal parasite diversity?
BUT
when phylogeny is controlled for, this relationship disappears, showing that body mass doesn’t explain parasite diversity and richness.

Instead, it seems that the main factor explaining primate parasite diversity is population density

In addition, geographic range seems to play a role, where a higher parasite diversity is found in primates with a larger geographic range.

Location

Question 239

How does geographical location affect parasite load

Answer 239

eg , higher protozoan parasite diversity is found in primates from tropical areas (not for helminths and viruses) where protozoan species richness is higher near the tropics than in temperate latitude.

Question 240

How did researchers studied how parasites were transmitted in primates

What was found with regard to diversity

Answer 240

Each parasite species was scored according to four major transmission strategies, including close contact,
on-close contact
(faecal to oral or fomites), vector-borne (spread by biting arthropods), or via intermediate hosts (i.e., parasites with complex life cycles or trophic transmission),

it was found that, in tropical areas, most of protozoans are transmitted by arthropods, who show a high diversity in these regions.

Question 241

How does the microbiome relate to sociality in primates

Answer 241

eg, in baboons, it was found that grooming networks predicted gut microbiome similarity, where individuals that groom frequently and maintained strong relationships via grooming had similar microbiome.

In the same way, microbiome similarity was predicted by interactions between social groups in a population of black and white colobus in Ghana

Microbiome similarity was predicted by sociality among sex-classes in a population of new-world monkeys, where microbiome was more dissimilar, so different, when individuals did not spent time in proximity or a lot of time together.

Question 242

Give 3 behaviours primates have developed to combat their high parasite load

Answer 242

making nests, in particular nests in specific trees that present anti-fungi or mosquito repellent properties, but also grooming is very efficient in removing external parasites like ticks
plants as self medication

Question 243

Give evidence of grooming helping to decrease parasite load

Answer 243

tick loads decrease as the number of grooming bouts received increases, in baboons.

Akinyi et al., 2013

Question 244

Give an example of chimp self medication

Answer 244

leaf swallowing, particularly hairy leaves, which remove gastro-intestinal parasites. These leaves are for example species of Manniophyton, which leaves have a lot of little thick hair that act like hooks. Chimpanzees make a ball of these leaves and swallow them without chewing.

Question 245

What are the stats showing primates are dying out

Answer 245

60% of primate species now are threatened and 75% of primate species have declining populations.

Question 246

What happens to forests if primates die out

Answer 246

primates are important seed dispersers as we have seen today, and so if there are no primates, we end up with empty forests, which are impossible to regenerate and host other species, and eventually perish

Question 247

What does it mean to say primates are an umbrella species

Answer 247

by conserving and protecting primates, one can protect and conserve their entire ecosystem

for example the presence of great apes in protected area increases the number of studies on other species, so by having great apes we get to know more about the entire ecosystem.

Question 248

If primates are going extinct, why should we care?

Answer 248

→ Primates are important seed dispersers
→ Primates are umbrella species
→ Primates tell us about our own evolutionary history

Question 249

Which primates are more likely to go extinct

what does this mean

Answer 249

rare species are more likely to go extinct
and specialist species are more likely to go extinct, but also species with large body mass are more
likely to go extinct due to their slow reproduction and the fact that smaller species are better able to
partition into space

because money allocated for conservation is limited, one needs to clearly identify priorities, which is to concentrate on biodiversity hotspots hosting the majority of vulnerable animal and plant species

Question 250

Give stats on world forests

Answer 250

forests cover 31 percent of the global land area. Approximately half the forest area is relatively intact, and more than one-third is primary
forest. More than half of the world’s forests are found in only five countries (the Russian Federation, Brazil, Canada, the USA and China)

Question 251

Give stats on deforestation

Answer 251

15.3 billion trees are chopped down every
year. 46% of the world’s trees have been cleared over the past 12,000 years. Between 2015 and
2020, the rate of deforestation was estimated at 10 million hectares per year, down from 16 million
hectares per year in the 1990s. The area of primary forest worldwide has decreased by over 80
million hectares since 1990.

: Large-scale commercial agriculture accounts for 40 percent of tropical deforestation between 2000 and 2010, and local subsistence agriculture for another 33 percent.

Question 252

Why is timber logging so bad

Answer 252

s many tropical trees are high price timber, such as ebony, mahogany and teak. Trees are selectively logged, leaving disturbed forest and leading to soil erosion due to logging roads, which cut the forest into parts, bring more people around and more exploitation

Question 253

Why will stopping buying beef help primates

Answer 253

Forests are burnt and transformed into cattle ranches

Question 254

Mining is a strong threat on primates and on the ecosystems. Elaborate

Answer 254

Rare minerals are extracted from tropical regions (e.g., coltan, gold). Local populations, particularly children, are exploited for extraction and these mines are creating huge soil erosion but also soil and water pollution

Question 255

Describe the risks of bush meat and wild animal pet trade

Answer 255

Exploitation of the world’s remaining tropical forests through overhunting is considered a major cause of biodiversity loss, in some cases more important than deforestation. The evidence is that exploitation of wild animals for food (bushmeat) by tropical forest dwellers has increased in recent years. This is due to growing human populations, greater access to undisturbed forests, changes in hunting technology, and scarcity of alternative protein sources. Pet trade encourages poaching and wildlife extraction

Question 256

How is human encroachment on primates bad

Answer 256

→ Associated with logging roads and agriculture
→ Increase proximity with wildlife
→ Increase risks of zoonoses
→ Associated with decrease of ape behavioural
diversity (loss of local animal cultures)

Question 257

What is one of the best ways forward for primate conservation

Answer 257

Conservation with local people

• Identify local needs
• Work together for sustainable livelihoods and improved healthcare
• Education programs and capacity building
• Report outcomes of projects, successes and failures

Question 258

Give an example of primates being deceptive

Answer 258

tactical deception is seen in capuchins who have been shown to give false alarm calls

(Wheeler, 2009)

Question 259

What spinal neural connections allow certain primates to use fingers with great dexterity

Evidence?

Answer 259

cortico-motoneuronal connections (direct, monosynaptic connections with motoneurons, bypassing the spinal interneurons.)

• projections to motorneurons appear in species that make independent finger movements (in primates) but are not seen in species without.
• Lesions of the corticospinal tract in the medulla leave permanent deficits that are most extreme in finger movement and manipulation.
• in man the direct projections post-natally, appearing at about 9 months. At this age dexterity begins to develop.

Question 260

What is key to understanding who chimps and bonobos will share with conspecifics

Answer 260

long-term contingency is proximately regulated by a ‘relationship score’ computed through a tally of past interactions which tend to outweigh recent single events
(Jaeggi et al., 2013)

Question 261

What are content based hypotheses of multimodal communication

Answer 261

redundancy hypothesis

complementarity hypothesis

Question 262

Explain the redundancy hypothesis of multimodal communication

Answer 262

different components of multimodal signals convey the same information and are thus redundant

multimodal signalling allows an increased accuracy of receiver response (Johnstone 1996) and provides insurance against imperfect sender coding

Question 263

Give evidence for the redundancy hypothesis of multimodal communication (3)

Answer 263

Cartmill and Byrne (2007):
orangutans adopted cross-modal tactics to achieve communicative goals, by repeating signals if they are partially understood and substituting gesture types and sensory modalities if completely misunderstood.

both simultaneously and sequentially redundant signalling might play a particular role in certain developmental stages in apes, as a mechanism in young individuals to increase signal efficacy (termed ‘repertoire tuning’ by Hobaiter and Byrne 2011).

Thus, the large body of evidence derived from great apes living in captive and wild settings led Byrne et al. (2017) to conclude that the apes’ gestural repertoire is widely redundant

Question 264

What is the complementarity hypothesis of multimodal communication

Answer 264

different infor-mation is conveyed in each channel (Fig. 1), resulting in an overall increase in information content

each element plays a different functional role and thus complements the other(s) (Partan and Marler 2005).

Question 265

What is the evidence for the complementarity hypothesis of multimodal communication in humans and non-primates

Answer 265

mixed evidence for complementarity from non-primate species (reviewed in Hebets and Papaj 2005)

human co-speech gestures can have independent communicative functions, Meaning is then derived through integrating the information conveyed in different channels

gestures serve as a cognitive aid, providing signallers with a second representational format to reduce cognitive load and serve as a tool for thinking and learning (Goldin-Meadow 1999).

Gesturing reduces demands on cognitive resources and frees capacity to perform other tasks (Goldin-Meadow and Wagner 2005). Thus, humans’ gestural and facial signals accompanying speech do not merely act to facilitate message detection and discrimination (i.e., redundancy), but rather increase the total amount of information available (Partan and Marler 1999).

Question 266

What is the evidence for the complementarity hypothesis of multimodal communication in primates

Answer 266

captive bonobos (but not chimpanzees) have been shown to be more responsive to multimodal (i.e., gestures combined with facial/vocal signals) than unimodal communication despite its rare usage, which led the authors to conclude that bonobos attempt to add information content rather than merely increasing efficacy (Pollick and de Waal 2007)

Question 267

What is the efficacy based hypothesis of multimodal communication

Answer 267

Hebets and Papaj (2005):

the ‘efficacy-backup hypothesis’, which states that each signal component acts as a backup to the other in the presence of environmental noise

does not relate to constraints in sender coding but to signal degradation and attenuation during transmission

Question 268

What is the difference between the efficacy backup and redundancy hypotheses

Answer 268

While the redundancy hypothesis assumes that additional signals increase the reliability of the message content, the efficacy-based backup hypothesis poses that additional signals increase the probability of a receiver response across a variety of environmental conditions

Question 269

What is the evidence for the efficacy based hypothesis of multimodal communication

Answer 269

use of a multimodal courtship display in wolf spiders consisting of visual and seismic signals, allowed males to gain as many copulations during dark as compared to light conditions, as well as on vibration-transmitting compared to dampening substrate (Hebets and Papaj 2005).

not yet systematically been tested in primates, probably due to the difficulty of designing the appropriately standardized experimental setups

Question 270

Give the difference between free and fixed multimodal signalling

Answer 270

‘Fixed’ multimodal signals are those whose components are obligatorily coupled due to the mechanics of signal production (e.g., a ‘scream face’ necessarily accompanies a ‘scream’ vocalization in chimpanzees).

By contrast, ‘free’ multimodal signal combinations are those whose components may be produced separately or combined flexibly with other signals (e.g., in chimpanzees’ greeting interaction, a submissive ‘pant grunt’ vocalization is occasionally accompanied by an ‘embrace’ gesture).

Question 271

Show that coupling of independent stimuli plays a vital role in human multimodal communication

Answer 271

the McGurk effect impressively demonstrates that our perception of auditory stimuli can be modified by visual stimuli

Question 272

What is a refinement hypothesis for multimodal communication

Answer 272

The ‘increased detection and discrimination’ hypothesis; Hebets and Papaj (2005)

the presence of one signal either increases the probability and/or speed of detection of a second signal (increased detection), or increases the accuracy with which the receiver responds to a second signal (increased discrimination)

The presence of one signal might thus provide a context in which a receiver can interpret and respond to a second signal.

Question 273

Give evidence of use of Inter‑signal interaction for refinement in apes

Answer 273

male bonobos use the same vocalization (‘contest-hoot’) in playful and aggressive contexts but add gestures to distinguish between the two (Genty et al. 2014), thereby clarifying an ambiguous message sent in one channel by adding a more specific component in another channel.

Thus, even in conditions of good visibility and plenty of social exposure (i.e., in captivity), signals of different sensory modalities are often combined into multimodal sequences or signal combinations

Question 274

Give evidence of refinement hypothesis in multimodal communication (3)

Answer 274

accompaniment of visual cues facilitates comprehension of auditory cues (Sumby and Pollack 1954).

Moreover, studies have shown that tactile stimulation can increase the degree of visual cortex activity and visual discrimination in humans

McGurk effect

Question 275

Give an example of how multimodal signals can affect humans

Answer 275

marble hand illusion

Senna (2014)