6. cooperative alliances

Question 1

altruism
-> benefiting another individual at a cost to onself

Answer 1

• psychological
  if there is an underlying motivation to increase the welfare of others
• biological
  actions that increase the reproductive success of others
  while reducing the fitness of the actor -> rare cuz selected against in evolution
• cooperation
  working together for mutual benefits

Question 2

altruism
-> 6 evolutionary explanations

Answer 2

1. mistake or by-product
   e.g. nurse salary, would they still help if they didn’t get paid?
2. kin altruism
   Help their offspring and kin because they share genetic material
   Inclusive fitness: hamilton’s rule c < rb
   C = cost to actor
   r = degree of genetic relatedness
   b = benefit to recipient
   Costs and benefits are measured in reproductive currency
3. reciprical altruism
   direct -> help someone if they can expect smth in retun
4. indirect reciprocity
   return from someone else than the direct recipient
5. costly signalling
   help because helping signals smth good about them -> peacock’s tail
6. group selection
   help at a personal cost for the good of the group
   biological / cultural selection

Question 3

kinship and survival

Answer 3

traditional societies
- mothers + grandmothers have an especially pronounced influence on the survival of children

Question 4

inheritance as kin altruism

Answer 4

• leave more estate to genetically related kin and spouses
• leave more to close kin than to distantly related kin
• leave more to offspring than to siblings

Question 5

reciprocal altruism

Answer 5

prisoner’s dilemma
- solution tit for tat
cooperate on the first move and every move after
never be first to defect / retaliate after the other has defected / be forgiving

conditions
- cost actor lower than benefit recipient
- recognize others and detect cheaters
- repeated play

adaptions for cheater detection?

social brain hypothesis

expanding circles
- our relationships form a hierarchical inclusive series of circles of increasing size but decreasing intensity

Question 6

altruism via indirect reciprocity

Answer 6

language
- tests people’s reputation through gossip
-> cheaters can be excluded from our circles

Question 7

two costly signal
altruism as peackock’s tail

Answer 7

1. darwin’s sexual selection hypothesis
   - suggests that altruim evolved as a mating signal such that individuals compete dor sexual partners by being generous
2. war heroism
   - found greater reproductive success
   - rated sexually more attractive
   - male more attractive than female war heroes

Question 8

group selection and altruism

Answer 8

selfishness beats altruism within groups
altruism beats selfishness between groups
the rest is commentary

genetic or cultural group selection