Buss, Chapter 9

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Buss, Chapter 9
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Reciprocal altruism

• Can evolve as long as altruism is paid back later
• Cheating problem why wouldnt people receive
  benefits and not pay back later?

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Prisoners dilemma

• Game theory simulation with different payoff for
  each outcome
• Prisoners' Dilemma
• Tit-for-tat strategy in iterated PD, cooperate
  until other defects, then retaliate if they
  resume cooperating, then cooperate until they
  defect againcontingent reciprocity

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Prisoners dilemma

• Tit-for-tat is an evolutionarily stable strategy
  if most of population use it, cant be displaced
  by a better strategy

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Cooperation in nature

• Vampire batsfood sharing
• Baboons and chimpsalliances (they apparently
  watch Survivor) mating success often depends
  on such coalitions for non-alpha males female
  help can depend on prior grooming

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Social contract theory

• To overcome potential advantage for cheaters
  (those who would gain but not reciprocate),
  humans evolved several adaptationscognitive
  capacities which can deter cheating

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Anti-cheating cognitive capacities

• Recognizing individuals
• Memory for previous cheating or reciprocation of
  others
• Ability to communicate wants/needs to others
• Ability to understand wants/needs of others
• Ability to represent costs benefits of various
  items of exchange

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Tests of social contract theory

• Wason selection task purely logical formulation
  not solved well by most
• ex. a b 2 3 If it has a vowel on
  one side, it must have an even number on the
  other side which cards would you turn over to
  verify if rule is being followed?

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Tests of social contract theory

• Another problem with same logical form If a
  person is drinking alcohol, then she must be 18
  or older
• Drinking beer drinking soda 25 16
• Which ones to turn over to verify whether someone
  is violating rule?

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Testing social contract theory

• Usually second version of problem results in many
  more people getting it right
• Tooby Cosmides second version activates an
  evolved cognitive adaptation for detecting
  cheaters, first version did not
• Thus, social contracts are things people can
  understand easily because of historical need to
  deal with these recurrent adaptive problems

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Co-evolution cheating

• If we evolved cheater-detection abilities, then
  cheaters should evolve better ways of avoiding
  detection
• If cheaters get more deceptive, our detection
  skills need to continually get better, and may
  develop ability to detect genuineness of emotion
  behind altruism

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Co-evolution cheating

• Brown Moore study
• X helps X does not help
• X does not seek credit
• X does seek credit
• Which to turn over to verify if rule being
  followed (Rule If X helps, then X seeks credit)?

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Brown Moore study

• Correct choices X helps X does not seek credit
• Logic is that if other side of X does not seek
  credit says X helps, then you have found a real
  altruist
• Most people do choose the cards that will allow
  them to detect an altruist

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Friendship

• A third possible explanation of some types of
  cooperation /or altruism (i.e., not based on
  sharing genes or reciprocal altruism)
• True friends do not expect or want immediate
  reciprocal payback, as that would make it seem as
  though they did not do the favor just because of
  the friendship

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Friendship

• Should behavior that benefits others, without
  cost to giver, be considered altruistic?
• Perhaps there is a continuum of cost, and helping
  behavior gets more likely toward the low cost end

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Bankers paradox

• To get loan, have to prove you dont need it!
• Choosing whether to help someone we may want to
  help most those who are in best position to help
  us later (i.e., less in need than others)
• How can we get around this limitation? Becoming
  irreplaceable is one solution

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Fair weather vs. true friends

• Fair weather friends desert when your need is
  highest
• True friends ones who are there in toughest times
• (I add true friends when toughest times most
  cost to them)
• true friends do not expect reciprocation

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Same vs. opposite sex friendships

• Males see opposite sex friendships as potential
  mating opportunities more than females do
• Same sex friendshipspotential rivalry
• Women gain protection from opposite sex friends
• Opposite sex friendships provide opportunities to
  learn about other sex

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Cooperative coalitions

• Can evolve as long as can control defection and
  free riding
• Punishment appears to be main mechanism
• Punitive sentimentmake slackers pay
• Most punitive attitudes held by those who
  sacrificed the most

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