Cooperation Flashcards
What is the definition of cooperation?
Joint action for mutual benefit (among kin and non-kin)
What are the 2 forms of cooperation?
1) The action benefits the recipient and the actor
2) Investment/altruism: The action benefits the recipient but incurs costs for the actor
What is selfishness?
Where the action harms the recipient but benefits the actor
What is spite?
Where there is a cost to both the recipient and the actor
What do we usually see in terms of cooperation in humans?
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
What are the characteristics of hunter-gatherer cooperation in terms of foraging:
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
How do we explain cooperation in nonhuman primates?
One of the causes for cooperation in nonhuman primates is kinship
What is the inclusive fitness theory/kin selection?
Natural selection favours behaviour that maximizes inclusive fitness (that is, the passing down of genes directly or indirectly)
Fill in the blank: “Would I lay down my life to save my brother? No, but I would to save _ brothers or _ cousins.”
2, 8
What is direct fitness?
Number of genome copies you pass directly onto the next generation via your offspring
What is indirect fitness?
Number of genome copies passed indirectly to the next generation via the offspring of your kin
What does kin selection theory predict and why?
There should be more cooperation in philopatric sex, because they are together at all times, and they are closely related
What are some examples of cooperation exhibited in the philopatric sex?
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
What are some exceptions to the theory that there is more cooperation in philopatric sex?
Bonobos are male philopatric, but exhibit strong F-F bonds
What type of cooperation is grooming?
Altruism, where it is harmful to the actor in the sense that they are spending energy without receiving an immediate benefit
What is the data on kin biases in behaviour and grooming?
1) Most instances of grooming are between mother and infant
2) Grooming occurs most often between kin than distant or non-kin
How is relatedness measured?
R (coefficient of relatedness), which is always a fraction except for in the case of identical twins
What is Hamilton’s rule?
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
What is the data on kin biases in behaviour and coalitions/alliances?
Forming alliances/coalitions is more likely amongst close kin
What type of cooperation is coalition/alliance formation?
Altruism, where winning may result in victory of a dominance contest, but there is risk of injury
Explain the study on captive Japanese macaques that depicted kin biases in coalition formations
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
What are the 3 proposed mechanisms of kin recognition?
1) Phenotype matching, based on odor and sight (visual similarity)
2) Familiarity via maternal relationships
3) The paternal-relationship problem
What primates is kin discrimination by odor particularly found in?
Strepsirrhines, which have more elaborate olfactory communication than other primates
What is the source of secreted chemicals from lemurs?
Antebrachial glands on their arms
What information can a scent carry:
1) Identity of individual
2) Proximity to ovulation
3) Duration of pregnancy
What is the relationship between chemical composition and relatedness and what are the implications?
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
What is the genetic compatibility hypothesis?
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
Explain maternal association as a mechanism for kin discrimination
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
What is the paternal relationship problem?
Promiscuous matings create paternity confusion
Can fathers recognize their biological kin?
Yes, through mechanisms unknown
What is the data on paternal recognition of kin?
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
What are some examples of non-kin cooperation?
1) Contingent reciprocity
2) Biological markets
3) Byproduct mutualism
4) Manipulative mutualism
What is contingent reciprocity?
“Helping pays if the beneficiary returns the favour”
What is an example of contingent reciprocity?
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
What is reciprocal altruism?
B reciprocates A’s altruism because they have a long term relationship
How is contingent reciprocity maintained?
1) Punishment
What is an example of punishment for failing to reciprocate altruism?
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
What is the effect of competition on reciprocity?
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
What is the hypothesis of biological markets?
Individuals with something valuable can command a market of altruism
What is the effect of absence of market on reciprocity?
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
What is byproduct mutualism?
Where an individual’s selfish actions incidentally benefits others
What is the collective action problem?
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
How is the collective action problem solved (i.e., how does hunting in groups increase per capita meat intake)?
Through byproduct mutualism
What is responsible for the emergence of byproduct mutualism?
The presence of impact hunters (hunt catalysts), who are the ones to initiate hunts most frequently thus reduces costs for other hunters
What are the characteristics of an impact hunter?
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
Why are some males impact hunters?
1) Personality
2) Act in an attempt to obtain more meat
What is manipulative mutualism?
Where individual B affects the payoff structure such that cooperation is immediately beneficial to individual A
What is the definition of sharing?
Joint use of monopolizable food items, where the food owner has a choice to give or keep
Describe patterns of food sharing in wild primates
Most frequent with kin
1) Parent/offspring sharing
2) Sibling provisioning
Where is food sharing with mates seen most?
In most, but not all, monogamous societies (birds, humans)
Which monogamous species do not exhibit food sharing with mates?
Gibbons
Describe food sharing between mates in owl monkeys (Aotus)
1) Mainly male to female
2) Sharing is increased when the female needs more food (during pregnancy, but especially during lactation)
Describe food sharing amongst nonkin in bonobos
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
Describe food sharing amongst nonkin in chimpanzees
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
Describe the results that “proved” chimpanzees exchanged meat for sex
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
Describe the results that disproved the meat-for-sex theory
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)
What were the fundamental flaws in the meat-for-sex hypothesis?
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)
What is the demand-sharing theory?
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
What are predictions associated with the demand-sharing theory?
1) Harassment by beggars must be costly to possessor
2) Harassment elicits sharing
3) Sharing results in a decline of harassment
Describe the characteristics of tolerated/theft and demand sharing
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
