Lecture 8 (Altruism) - Slides Flashcards
Altruism
- Action whose average effect is to benefit someone else at some cost to the actor.
- Both costs and benefits measured in expected fitness
- Altruism among non-kin can occur through:
1) Reciprocity
2) Costly Signalling
Reciprocity
- Altruism among non-kin
- Can be direct or indirect
1) Direct Reciprocity: Preferentially help those who have provided help in return.
- Video: Blood meals in vampire bats. Bats who refuse to give a neighbor a blood meal, receive less in return. Reciprocal altruism in non-related organisms by proximity
- Linguistic evidence: Many phrases that represent this idea (tit for tat, quid pro quo, etc…
- Prisoner’s Dilemma, Tit for Tat, Emotional regulation
- Common Pool Resources: Does not explain cooperation in the context of common/public goods (see slide)
2) Indirect Reciprocity: Altruistic acts that are unlikely to be directly reciprocated, but may be rewarded via reputational effects. People like those who are altruistic, even to others.
- 2nd order punishment, game, costly signalling (hunting and hunter-gatherers), eyes, charity
Prisoner’s Dilemma
- Pay-off matrix and game
- Illustrates how direct reciprocity sustains cooperation
- Both cooperate = 1 year of prison each, one defects:one cooperates 10:0, Both defect = 5 each
- Player A should defect, but so should B
- When both defect they get a worst payoff, so in the long run (multiple games with the same individual) it pays off to cooperate
- Because you don’t want your defection to come and bit you later and also it sustains cooperation longer
Tit for Tat
3 keys and what it can be called
- Can also be called direct reciprocity
1) Never be the first to defect
2) Retaliate only after the other has defected
3) Resume cooperation when the other does
Emotional Regulation
- How reciprocity is sustained
- Cooperation is regulated by emotions and our feelings about others:
Emotions that influence reciprocity include: Friendship/emotions of liking and disliking - Moralistic aggression
- Gratitude & sympathy
- Guilt
- Trust & suspicion
Problem with Reciprocity
- Reciprocity doesn’t usually happen simultaneously, so we have to hold information of individuals who we know owe us and who we might owe
- This can lead to cheating
- Cheating can be advantageous in a population with lots of cooperators
- Cheater detection necessary for evolution of altruism in non-kin
- Oda et al. 2009, Barclay 2008
Oda et al. 2009
Can we detect altruists?
- Males asked how often they performed altruistic acts
- The 7 highest/lowest scorers were video taped and sound was removed.
- Used questions which had the greatest difference in response used to determine altruism
- Another group took the altruism survey and watched the videos and rated how altruistic the video participants were
- Results: High altruists gave higher altruist scores to videos. Altruists were ranked as more altruistic that non-altruists
- Altruists were judged as more socially active, generous, responsible, friendlier and kinder
- But NO difference in: discreetness, hurriedness, and intelligence. Intelligence is important because it shows it’s not a halo effect.
Barclay 2008
Can we detect cheaters?
- Trust game: P1 can not trust P2 and give $10 to each participant, or trust and P2 will share a $30 pot equally.
- P2 is computer with photo
- P2 either: 1) cooperate which gives $15 each, or defect which gives P2 20 and P1 5
- Encoding phase: 40 random opponents, did not repeat the same opponent and defection rate of opponents varied by 20/50/80%
- Distractor task: 10 minute demograhpic survey
- Recall phase: Unexpected facial recognition task (40 previous faces, 40 new faces), asked to classify as: Novel/Recognize and Cooperator/Defector
Results: When defectors are rare (20%), they are recalled more accurately than are competitors. Effect reverses when cooperators are rare.
- Suggests that when a strategy is rare, we are more likely to remember those who employ that strategy. We remember rare more.
- Because: Whatever behaviour is more common, it’s likely to represent the social norm (reduces cognitive load since you have to remember more)
- When defectors = 50%, our memory for cooperators has an advantage. Could be a bias towards seeking cooperators, but most people cooperate more anyways.
- From brief silent video clips, we can identify unknown altruists at rates higher than chance
Common Pool / Public Goods
- A resources that gets depleted with each use and used by a large group of people
- No direct reciprocity possible: use you are not helping in return or expecting to help in return.
- About how you -allocate- those common goods
- Invite cheaters
- Tragedy of the commons
- Economic rationality vs. enlightened self-interest
Tragedy of the Commons:
- Common ground where livestock can graze and each herder can bring some, but not all livestock
- The more you use it the more it’s depleted and the damage is shared by the group
- Economically rational: graze without regard of what is left over
- Enlightening self-interest: by limiting your own profits, you are helping yourself. Because if you all graze at once, it precludes your ability to graze in the future.
- Those who pay are “suckers”/tragedy of commons, so its in the cooperators best interest to develop ways to detect cheating.
Tragedy of the Commons in the Lab
Game, 2 effects and manipulations
- Groups of 4 subjects play a game where they receive $20 to keep or donate to the common pool.
- Donations doubled the pot and were equally distributed among players.
- Example: If all donate $20, pool = 80*2 = 160, Each get 40
- But if 1 free-rides, Pool = 60*2 = 120, each get $30 but 1 gets 30+20=50
- Reputation, Punishment effect manipulations (see slides)
proximate mechanism (emotions). - Results: Most donate most of their money %50
- Donations fall over successive rounds, especially final round when end-game is known.
Reputation Effect
and game
- Commons game manipulation
- Reputation Effect: manipulated anonymity and reputation (one group was anonymous, one met their group and were told their results would be told to the others later.
- Participants gave in non-anonymous/reputation manipulation
Punishment Effect
game and order
- Punishment Effect: After each round participants could pay 1 to reduce payout to other player by 3.
- Free riders will never punish or cooperate because both are costly, without benefit
- Free rider punishment is altruistic because it will never benefit the punisher, only future players who play them
- 6 rounds, different players, anonymous (no reputation/reciprocity effects)
- Results: 84% punish at least once, 74% were imposed on free riders by cooperators
- Punishment was harsh, group spent on average, $10. - The less contributed/cheated, the greater the punishment (reflective of our criminal justice system)
- Punishment created more cooperators and no dip at the end of rounds
- Without punishment there was reduced cooperation and a decline to later rounds.
Proximate mechanisms for cooperation & punishment
- Emotion
- Experiment: Scenario where a school project member contributes significantly less to the project, how angry would you be? (1-7). 84% > 5.
- Free-riding makes people angry and the exclusion of a social group may maintain cooperative behaviour.
2nd Order punishment
- Costly punishment maintains contributions to public good and without it, contributions decline over time.
- Problem: Temptation to let others punish while keeping your share (2nd order). Do we punish non-punishers?
- Experiment: the more they contribute collectively, the more they get in return shares, they see how much every player gives, and are allowed to punish. 50% punish, in the next round, only 2% punish. No 2nd order punishment effect.
Dictator Game
Indirect Reciprocity
- Share money with another player, no chance for reciprocity with a second round, but you have a reputation because your donation history is displayed.
- Never repeated rounds with the same person.
- Image score = reputation score (higher score = more donations and more often)
- 7/8 donated more to those who donated
- More altruism = more helping
Costly Signalling
- Expensive signals are designed to convey honest information (because of how expensive it is, it must take away from other things)
- Example: Facial masc. is a costly signal that conveys info about the male
- Signals must convey reliable info (about underlying quality)
- Must impose a cost on signaler that is linked to the quality being advertised
- Either lower quality signalers pay higher cost, or reap lower benefits
- Sport hunting, turtles, eyes,
Sport Hunting
- Underlying psychology of modern hunting may come from costly signalling in sport hunting. (To hunt for a trophy is useless and not for survival. Demonstrates proficiency of animal-killing).
- Displays expertise, prowess, vigor
: Conditions required: Difficult to succeed, success in public information,rep. built on success, and benefits the hunter
Traditional Hunting
and turtles + alternative explanation
- Traditional hunting is unreliable & dangerous and provides fewer calories than foraging
- Meat is typically shared without preference to family or hunter (Divided and given to community)
- Success as a hunter doesn’t predict DIRECT reciprocity
- Turtle Hunting: 2 types (jumper/captain)
- Turtle hunters donate meat to public feasts in an uncontrolled manner and hunters are not compensated
- Hunters reap reproductive benefits (more surviving offspring, more mates, harder working mates and younger partners)
- A lot of gossip goes on about who was a successful or good under and the group find outs quickly.
- Leaders have more children than hunters but hunters more than non-hunters across all ages
- At younger ages, not much differences between leaders and hunters
- Alternative explanation? Hunters are higher genetic quality?
- No effect of genetic quality = non-hunting brothers have significantly lower reproductive success even though they should have similar genetic quality and RS
- All that matters is you are a hunter for your RS, not any genetic value
- Seems to really be about reputation.
Costly Signaling (eyes, charity work)
- Eyes: Unattended coffee was placed on campus, asked people to pay for what they take
- Had pictures of eyes and flowers in front of coffee
- Measured how much people paid with eyes/flowers in front of them
- Gave more when there were eyes instead of flowers
- More free-riding when people think they are being watched
- Which eye photo it was did not matter.
- Charity Work: In seminar groups (people knew each other but were not friends so there was a higher likelihood of future encounters)
- Asked them to sign up for charity work anonymously/publicaly.
- Charity tasks varied with degrees of commitment (giving blood to health care for mentally disabled children)
- An audience effects what kind of charity you will do:
- If you were forced to volunteer publically, more individuals volunteered for costly activities, if anonymous, smaller activities.
Psychopathy
Personality Disorder and Epidemiology, Impairment
- Personality Disorder: Antisocial behaviour, lack of empathy, manipulative, violent, selfish (many traits antithetical to altruism)
- Epidemiology:
Rare (1%), mostly males, and over-represented in psychiatric and prison populations - Examples: John Wayne Gacy, and Kenneth Bianchi
- Not classified in the DSM. Different than antisocial personality disorder
- Can be a psychopath with no criminal record (CEO)
Impairment
1) Behavioural: higher criminal violence
2) Physiological: impaired startle response
3) Emotional: Lack of empathy/remorse/guilt
4) Cognitive: Emotions (see experiment)
Psychopathic offenders
compared to non-psychopaths
- More likely to commit crimes in the future when they are let out
- Commit different kinds of crimes (never crimes of passion)
- Mostly instrument crimes: 93% commit homicides vs. 78%, involve weapons and violence and more likely to kill non-kin and complete strangers (because not passion)
- 2.5x more likely to get conditional release (implies manipulation and dangerous because they also have a higher likelihood to re-offend)
Psychopath Experiment
Hare 1991
- Experiment: Measured criminal psychopathy with 20 item checklist score ranges from 0-40 (25+ = psychopath)
- Items include glibness/superficiality, impulsive behaviour, etc.
- Measured selfishness/callous/manipulativeness and emotional factors
- Looked at pictures of eyes and asked what emotions those people were feeling
- People with the highest psychopath scores were less accurate at determining the emotion (less ability to empathize and understand what others are feeling)
- Controlled for gender, IQ, attention, working memory
- Can mimick emotion without having anything underneath to understand it. Might be why they can be manipulative without understanding it.
Psychopathy vs. Antisocial Personality Disorder
- Considerable overlap between constructs
- APD is over-inclusive, and if scored similarly, they correlate highly
- Differences are: Psychopathy includes APD but places less emphasis on age of onset and other specific criminal behaviours
Psychopathy vs. Sociopathy
- Not synonymous with psychosis
- Sociopathy differs with regard to etiological underpinnings
- Differences may be linguistic
- Sociopathy seems to have more lack of being in touch with reality and implies an environmental effect as opposed to genetic
2 Explanation of Psychopathy
1) Psychopathy as psychopathology (developmental/environmental effects influencing behaviours)
- Treat psychopaths as people with disturbed development
- But improving emotional/social functioning for them can increase violent recidivism
- Because they are taught how to better manipulate individuals (learning the rules = seeing it as a game to be won)
- Evidence:
1) Developmental delay - EEG patterns are more similar to children
- Early brain damage/dysfunction evidence to frontal lobes
- Correlations between poor socialization/physical trauma (poverty, emotional instability, inconsistent punishment/abuse)
2) Psychopathy as an special design:
- Characteristics are not deficits or impairments
- Organized, functional phenotypic features
- Could be an ESS: cheaters are successful when they are difficult to detect, highly mobile, verbally skilled (especially when persuading females to mate), AND rare.
- Sexual coercision aspect of psychopathy can explain why it could have been maintained in evolutionary history
- Lalumier et al, 2001
Lalumier et al. 2001
What the 2 explanations would predict
- Psychopathology: Should show signs of developmental pertubations
- Special design: Should not
-Measured facial FA, and obstetrical problems (difficulties during pregnancy: during pregnancy pre-post delivery, labor, birthweight) - all are good predictors of developmental problems in general)
- Analyzed clinical/medical records of 800 male offenders
- Gave them a psychopath test (PCL-R)
- Psychopaths have less developmental (obstetrical problems) than non-psychopaths signficiantly
- FA is significantly different in non-psychopath offenders to non-offenders but no difference in psychopaths to non-offenders
- Problem: Doesn’t directly support psychopathy as a special design
Altruism Summary
- Reciprocity: We help those who help (us or anoyone else) and punish those who don’t
- Costly signalling: Generosity serves as signal to phenotypic quality
- Psychopathy: Successful cheater strategy a frequency-dependent solution
