Cooperation

Question 1

What is the definition of cooperation?

Answer 1

Joint action for mutual benefit (among kin and non-kin)

Question 2

What are the 2 forms of cooperation?

Answer 2

1) The action benefits the recipient and the actor
2) Investment/altruism: The action benefits the recipient but incurs costs for the actor

Question 3

What is selfishness?

Answer 3

Where the action harms the recipient but benefits the actor

Question 4

What is spite?

Answer 4

Where there is a cost to both the recipient and the actor

Question 5

What do we usually see in terms of cooperation in humans?

Answer 5

There is typically a natural division of labour, for example in the context of food-gathering, which is not seen in other primates such as chimpanzees

Question 6

What are the characteristics of hunter-gatherer cooperation in terms of foraging:

Answer 6

1) Far more cooperation than non-human primates
2) On average, cooperative foraging can take up less than an hour of an individual’s day
3) Hunter-gatherers can spend up to a maximum of 50% of their day cooperatively foraging
4) Both sexes cooperate roughly equally

Question 7

How do we explain cooperation in nonhuman primates?

Answer 7

One of the causes for cooperation in nonhuman primates is kinship

Question 8

What is the inclusive fitness theory/kin selection?

Answer 8

Natural selection favours behaviour that maximizes inclusive fitness (that is, the passing down of genes directly or indirectly)

Question 9

Fill in the blank: “Would I lay down my life to save my brother? No, but I would to save _ brothers or _ cousins.”

Answer 9

2, 8

Question 10

What is direct fitness?

Answer 10

Number of genome copies you pass directly onto the next generation via your offspring

Question 11

What is indirect fitness?

Answer 11

Number of genome copies passed indirectly to the next generation via the offspring of your kin

Question 12

What does kin selection theory predict and why?

Answer 12

There should be more cooperation in philopatric sex, because they are together at all times, and they are closely related

Question 13

What are some examples of cooperation exhibited in the philopatric sex?

Answer 13

1) Macaques are female philopatric and form strong coalitionary alliances, often against males
2) Chimpanzees are male philopatric and cooperate during border patrols, as well as form coalitions

Question 14

What are some exceptions to the theory that there is more cooperation in philopatric sex?

Answer 14

Bonobos are male philopatric, but exhibit strong F-F bonds

Question 15

What type of cooperation is grooming?

Answer 15

Altruism, where it is harmful to the actor in the sense that they are spending energy without receiving an immediate benefit

Question 16

What is the data on kin biases in behaviour and grooming?

Answer 16

1) Most instances of grooming are between mother and infant
2) Grooming occurs most often between kin than distant or non-kin

Question 17

How is relatedness measured?

Answer 17

R (coefficient of relatedness), which is always a fraction except for in the case of identical twins

Question 18

What is Hamilton’s rule?

Answer 18

1) c < b x r
2) Behaviour (altruism) is favoured by natural selection when benefits of the act (in terms of indirect fitness) exceeds the cost of the act

Question 19

What is the data on kin biases in behaviour and coalitions/alliances?

Answer 19

Forming alliances/coalitions is more likely amongst close kin

Question 20

What type of cooperation is coalition/alliance formation?

Answer 20

Altruism, where winning may result in victory of a dominance contest, but there is risk of injury

Question 21

Explain the study on captive Japanese macaques that depicted kin biases in coalition formations

Answer 21

1) Juveniles were put in an enclosure without adults, such that they established a dominance hierarchy on their own
2) Kin (mother, grandmother, aunt) were added into the enclosure
3) When juveniles faced a more dominant opponent, kin tended to intervene such that the juvenile would rise in rank
4) Interventions were most likely with mothers > grandmothers > aunts
5) The juvenile did not rise in rank when the aunt was added to the enclosure

Question 22

What are the 3 proposed mechanisms of kin recognition?

Answer 22

1) Phenotype matching, based on odor and sight (visual similarity)
2) Familiarity via maternal relationships
3) The paternal-relationship problem

Question 23

What primates is kin discrimination by odor particularly found in?

Answer 23

Strepsirrhines, which have more elaborate olfactory communication than other primates

Question 24

What is the source of secreted chemicals from lemurs?

Answer 24

Antebrachial glands on their arms

Question 25

What information can a scent carry:

Answer 25

1) Identity of individual
2) Proximity to ovulation
3) Duration of pregnancy

Question 26

What is the relationship between chemical composition and relatedness and what are the implications?

Answer 26

Individuals who are closely related have a smaller chemical distance than those who are distantly/not related, thus odor could allow kinship estimation among breeding males

Question 27

What is the genetic compatibility hypothesis?

Answer 27

1) Chemical profiles could be guiding male-male competition and female mate choice
2) Dissimilarity between mates increases the fitness of offspring, therefore “smelling similar” may detract from mating

Question 28

Explain maternal association as a mechanism for kin discrimination

Answer 28

1) Mothers recognize offspring by proximity
2) Mothers and offspring learn to identify each other via sight/sound/smell
3) Offspring treat familiars of mother as kin

Question 29

What is the paternal relationship problem?

Answer 29

Promiscuous matings create paternity confusion

Question 30

Can fathers recognize their biological kin?

Answer 30

Yes, through mechanisms unknown

Question 31

What is the data on paternal recognition of kin?

Answer 31

1) Researchers measured difference in amount of time spent helping biological offspring versus behavioural offspring
2) Males supported their own offspring in conflicts more than their behavioural offspring

Question 32

What are some examples of non-kin cooperation?

Answer 32

1) Contingent reciprocity
2) Biological markets
3) Byproduct mutualism
4) Manipulative mutualism

Question 33

What is contingent reciprocity?

Answer 33

“Helping pays if the beneficiary returns the favour”

Question 34

What is an example of contingent reciprocity?

Answer 34

1) A grooms B
2) Playback of A’s distress call
3) B’s interest in A’s call increases compared to when no prior grooming has taken place

Question 35

What is reciprocal altruism?

Answer 35

B reciprocates A’s altruism because they have a long term relationship

Question 36

How is contingent reciprocity maintained?

Answer 36

1) Punishment

Question 37

What is an example of punishment for failing to reciprocate altruism?

Answer 37

1) Low-ranking adult male A discovers food
2) A gives food-call
3) Other males come, they share food, and no aggression occurs
4) If calls have not been made, and A had been caught, A would be attacked
5) Reciprocal altruism is vulnerable to defection - the relationship can fall apart if no reciprocation takes place

Question 38

What is the effect of competition on reciprocity?

Answer 38

1) In a despotic environment where food is monopolizable, there are high rates of aggression
2) Grooming is asymmetrical down the rank hierarchy, as grooming tends to be exchanged for coalitionary support
3) Presence of competition suppresses reciprocity

Question 39

What is the hypothesis of biological markets?

Answer 39

Individuals with something valuable can command a market of altruism

Question 40

What is the effect of absence of market on reciprocity?

Answer 40

1) In an egalitarian environment, where there is only scramble competition and little aggression
2) Grooming is symmetrical
3) Absence of market allows for reciprocity

Question 41

What is byproduct mutualism?

Answer 41

Where an individual’s selfish actions incidentally benefits others

Question 42

What is the collective action problem?

Answer 42

1) In a group, there are only some who act while others benefit (e.g., some hunt more than others)
2) This set-up favours free-riding, where some individuals obtain benefits without paying any cost
3) Thus, the collective benefit is reduced

Question 43

How is the collective action problem solved (i.e., how does hunting in groups increase per capita meat intake)?

Answer 43

Through byproduct mutualism

Question 44

What is responsible for the emergence of byproduct mutualism?

Answer 44

The presence of impact hunters (hunt catalysts), who are the ones to initiate hunts most frequently thus reduces costs for other hunters

Question 45

What are the characteristics of an impact hunter?

Answer 45

1) Tend to hunt first, more frequently
2) Hunts are more likely to occur for any given party size in the impact hunter’s presence
3) Hunts are initiated less frequently in the absence of an impact hunter
4) ~10% of males

Question 46

Why are some males impact hunters?

Answer 46

1) Personality
2) Act in an attempt to obtain more meat

Question 47

What is manipulative mutualism?

Answer 47

Where individual B affects the payoff structure such that cooperation is immediately beneficial to individual A

Question 48

What is the definition of sharing?

Answer 48

Joint use of monopolizable food items, where the food owner has a choice to give or keep

Question 49

Describe patterns of food sharing in wild primates

Answer 49

Most frequent with kin
1) Parent/offspring sharing
2) Sibling provisioning

Question 50

Where is food sharing with mates seen most?

Answer 50

In most, but not all, monogamous societies (birds, humans)

Question 51

Which monogamous species do not exhibit food sharing with mates?

Answer 51

Gibbons

Question 52

Describe food sharing between mates in owl monkeys (Aotus)

Answer 52

1) Mainly male to female
2) Sharing is increased when the female needs more food (during pregnancy, but especially during lactation)

Question 53

Describe food sharing amongst nonkin in bonobos

Answer 53

1) Share meat between communities (though carnivory is rare since they mostly eat large fruits)
2) 80% of food is possessed by females
3) There is no kin advantage in sharing, and sharing is mostly passive

Question 54

Describe food sharing amongst nonkin in chimpanzees

Answer 54

1) Meat sharing tends to be between males, or males share with females
2) Females do not hunt (would have their food stolen)
3) Several begging tactics (sit and stare, reach, pull)
4) Frequent passive sharing and sometimes active

Question 55

Describe the results that “proved” chimpanzees exchanged meat for sex

Answer 55

1) Hunting frequency increased if swollen females were present
2) 5 ‘unambiguous instances’ of males withholding meat until mating
3) Mating frequently observed after successful hunts

Question 56

Describe the results that disproved the meat-for-sex theory

Answer 56

1) Swollen females were not more likely to obtain meat
2) Sharing did not increase chances of mating
3) The presence of swollen females actually has a negative effect on hunting rates (i.e., males chose between meat OR sex)

Question 57

What were the fundamental flaws in the meat-for-sex hypothesis?

Answer 57

1) Chimpanzees are promiscuous (to create paternity confusion)
2) Females are often coerced by males and mate-guarded during their fertile period (females have limited choice)

Question 58

What is the demand-sharing theory?

Answer 58

1) For the possessor, the value of a remaining resource declines with time (e.g., because they get full, their nutritional requirements are met)
2) Defending food becomes costly
3) Allowing the beggar to take food saves costs of defense
4) In other words, manipulative mutualism

Question 59

What are predictions associated with the demand-sharing theory?

Answer 59

1) Harassment by beggars must be costly to possessor
2) Harassment elicits sharing
3) Sharing results in a decline of harassment

Question 60

Describe the characteristics of tolerated/theft and demand sharing

Answer 60

1) Recipients take from possessors and have some control over donors
2) Donors allow their food to be taken and offer minimal resistance
3) Recipient’s persistence/fighting gives high benefit and donor’s fighting gives low benefit
4) Favoured by lack of donor control