Cycle 8 - Cooperation and Conflict

Question 1

State the meaning of kin selection, altruism, reciprocal altruism

Answer 1

Altruism: helping someone at a cost to one’s self (true altruism is very unlikely)

Kin Selection: altruistic behaviour to close relatives, allowing them to produce proportionately more surviving copies of the altruist’s genes

• Extent of altruistic behaviour exhibited by one individual to another is directly proportional to the percentage of alleles they share

Reciprocal Altruism: form of altruistic behaviour in which individuals help nonrelatives if they are likely to return the favour in the future

Question 2

State the degrees of relatedness

Answer 2

1. Sibling, offspring, parent r = 0.5
2. Half sibling, nephew, niece, aunt, uncle, grandparent r = 0.25
3. First cousin, great-grandparent r = 0.125
4. Second cousin r = 0.0625

Question 3

Explain cooperation, selfishness, altruism, and spite

Answer 3

Question 4

Why are “altruistic” and “spiteful” behaviours both difficult to reconcile with natural selection?

Answer 4

Both behaviours reduce the actor’s lifetime reproduce success (fewer alleles passed on), so the behaviour should not be favoured

Question 5

Explain kin selection theory

Answer 5

Kin selection theory changes the way we think about fitness (i.e. we can’t just consider individual reproductive success, we must consider total fitness/inclusive fitness)

Direct fitness: number of surviving offspring

• Helping direct descendents +

Indirect fitnesss: individuals that survive or have the opportunity to reproduce who are non-descendent relatives

• Helping relatives +

Question 6

Explain how the evolution of trust and cooperation between UNRELATED individuals is affected by:

1. starting distribution of strategies
2. payoff matrix associated with cooperating vs cheating
3. the possibility of repeated interactions between the same two individuals
4. the risk of miscommunication and mistakes

Answer 6

1. starting distribution of strategies

• The fewer repeat interactions there are, the more distrust will spread
• Zero-sum game: a gain for us must come at a loss to someone else
• Non-zero sum game: people try hard to create a win-win situation or avoid a lose-lose situation – allows trust to evolve

2. payoff matrix associated with cooperating vs cheating

• Trust is nice, but it can let others take advantage of you
• Sometimes distrust is rational (it pays to cheat)
• In the long run cooperate pays off because both individuals benefit

3. the possibility of repeated interactions between the same two individuals

• If all individuals cheat, distrust will evolve
• If all individuals cooperate, trust will evolve

4. the risk of miscommunication and mistakes
   * Miscommunication is a barrier to trust - a little bit of it leads to forgiveness, but too much leads to widespread distrust

Question 7

Explain Beth’s rule

Answer 7

• r1 = focal individual’s relatedness to the recipient (ex., mom is 0.5)
• r2 = focal individual’s relatedness to the helper (their relatedness to me)
• b = benefit to the recipient
  
  • If b differs, conflict can arise
  • I.e., if my parents will incur a benefit if I help my brother but I incur a cost, there is disagreement
• c = cost to the helper (me)

Question 8

State conditions that favour or disfavour helping non-relatives

Answer 8

• Short-term interaction disfavours cooperation
• Non-zero sum game favours cooperation – mutual helping better than mutual punishment
• Repeated interactions in a small, stable community (where one can recognize helpers and cheaters) favours cooperation
  
  • Allows the ability to recognise and reward helpful individuals, as well as the ability to recognise and punish or avoid cheaters and free-riders

Question 9

Note: person you aren’t related to always wants you to help