Comparative Morality. Psychology 485 March 30, 2010. Outline. Introduction & Philosophy of Morality Group Living & Cooperation Altruism Game Theory Moral Instinct? Ultimatum game Fairness and empathy in animals.
March 30, 2010
“the difference in mind between man and the higher animals, great as it is, certainly is one of degree and not of kind”
"Of all the differences between man and the lower animals, the moral sense or conscience is by far the most important"
Altruism in non-kin
Expectation of ‘returning the favour’
Detection of cheaters?
Would behaviour evolve cheating was common?
Mathematical approach to multi-agent interaction
Specifies what agents should do to maximize their payoffs against rational agents
Stable solution to game theoretic problems
Evolutionary stable solution (ESS)
2 suspects caught by police
Cooperate (stay silent)
Defect (testify against other guy)
Players should always defect
Nash equilibrium does not equal globally optimum solution
Can cooperation be elicited if game is played multiple times?
If total number of trials is known, continue to defect
Should defect on last trial, since no opportunity for other player to “punish”
If both will defect on last trial, should defect on 2nd last… etc.
If total number of trials is not known, defection may not be dominant strategy
Tit-for-Tat: Cooperate, then copy
Studies show that animals tend to defect, even in iterated problems
Stephens, McLinn & Stevens (2002)
IPD with blue jays
Food held in ‘accumulator’ to reduce discounting
Cooperate in Tit-for-Tat strategy
Moral values change with cultural & lifestyle
e.g. smoking, working mothers, divorce, homosexuality
Health vegetarians – don’t eat meat for practical, health reasons
Moral vegetarians – don’t eat meat for ethical reasons
More likely to see meat as ‘contaminant’, believe other people should be vegetarians, associate vegetarianism with other virtues (less aggressive)
But “instinct” or gut-feelings seem to have control:
Moral Dilemma 1a:
A surgeon walks into the hospital as a nurse rushes forward with the following case. “Doctor! An ambulance just pulled in with 5 people in critical condition. Two have a damaged kidney, one a collapsed lung and one a completely ruptured liver. We don’t have time to search for possible organ donors, but a healthy young man just walked in to donate blood and is sitting in the lobby. We can save all five patients if we take the needed organs from this young man. Of course, he won’t survive, but we will save all five patients.”
Is it morally permissible for the surgeon to take this young man’s organs?
Moral Dilemma 1b:
A train is moving at a speed of 150 mph. All of a sudden, the conductor notices a light on the panel indicating complete brake failure. Straight ahead of him on the track are five hikers, walking with their backs turned, apparently unaware of the train. The conductor notices that the track is about to fork, and another hiker is on the side track. The conductor must make a decision: He can let the train continue on its current course, thereby killing the five hikers, or he can redirect the train onto the side track and thereby kill one hiker, but save five.
Is it morally permissible for the conductor to take the side track?
“no!” to question 1 (organs)
“yes!” to question 2 (trains)
Parallel structure, same calculus
What’s the difference?
Hints at moral intuition
Search for Universal Moral Grammar
Parallel to language
Julie is traveling in France on summer vacation from college with her brother Mark. One night they decide that it would be interesting and fun if they tried making love. Julie was already taking birth-control pills, but Mark uses a condom, too, just to be safe. They both enjoy the sex but decide not to do it again. They keep the night as a special secret, which makes them feel closer to each other. What do you think about that — was it O.K. for them to make love?
Broken down into 5 main themes:
If morality is “built-in”, based on instinct, parts of human morality may have precursors in animal behaviour
Moral building blocks?
Focus on 2 dimensions:
Rhesus monkeys trained to pull a chain for food reward
Now response leads to another monkey getting shocked (in addition to food)
Monkeys will go hungry for days
Masserman et al (1964)
Rats trained that pressing a lever lowered a styrofoam block
Tested with “suspended rat”
All rats worked to lower the other rat
Rice & Gainer, 1962
Player 1 is given $100, must offer a split to Player 2
Player 2 can accept or reject offer
If reject, neither player gets any money
Rational: Accept anything
But, offers less that 20% are often rejected
Why? Violates principle of ‘fairness’
Chimp version of ultimatum game
Jensen, Call & Tomasello (2007)
Must work together to pull in food reward
Chimps rarely refused offers
“Any animal whatever, endowed with well-marked social instincts, the parental and filial affections begin here included, would inevitably acquire a moral sense or conscience, as soon as its intellectual powers had become as well developed, or nearly as well developed, as in man.”