Week 10 competitive altruism

Evidence from public goods games that cooperative people are chosen more often then non-prosocial people

Barclay (2004): those who ranked highest in donation amounts the most chosen as a partner in the next round, and the lowest ranked were the least chosen

Using Tinbergen's 4 questions, what is the cause and mechanism through which competitive altruism acts?

Being observed because we care about reputation

Evidence that people alter their behaviour when observed and their reputation matters

Bereczkei et al (2007): there were more volunteers when it was public compared to private (raise hand versus write name); Bateson et al (2006): people donate more when there are watching eyes

Using Tinbergen's 4 questions, what would be one of the ultimate causations of competitive altruism?

Evolutionarily, people who were more prosocial had higher survival values because their altruism allowed for access to more partners

Evidence from public goods games that people will alter their behaviour when not anonymous and that those who are more cooperative are less preferred

In PGG games, when people can see which players donated more to the public pot, they are chosen by others in the group to play the next round and free-riders are ostracised

What are the 3 assumptions of competitive altruism?

Individuals vary in quality of altruistic behaviour, people can choose partners, and their altruistic behaviours provide public information

What does Raihani & Smith (2005) show us about competitive altruism?

It shows us that competitive altruism is a courtship display because men only donated to significantly more to an attractive female when there was a previous male donor (they wanted to out-compete the other male donor, which didn't happen when the previous donor was a female, who they would not have seen as competition)

What is the evidence that cooperation is a courtship display?

People increase their cooperation when with an attractive person of opposite sex and people rate cooperative others as more attractive

What is the evidence that people's behaviours provide public information about them?

People use public information to make judgements about a person. Bereczkei et al (2007): people who volunteer publicly were socially preferred compared to those who did not . Sommerfeld et al (2008): people write more positively about co-operators in a game than they do defectors/ free-riders. Lyle et al (2009): blood donors are considered as more generous than non-blood donors

Evidence from public goods games that cooperative people benefit from their cooperative behaviour

Sylwester & Roberts (2010): people who were more prosocial --> go on to next round --> more money accumulated by the end of the game

Explain Raihani & Smith (2005)

When donating to people raising money for a race, males would donate more to attractive females when there was a previous male donor who donated to the same woman

What is the evidence that individuals differ in their quality of altruistic behaviour?

When playing games public goods games, people some people will be free riders (not donating anything), conditional co-operators, and unconditional co-operators

What are 3 things we expect to see if competitive altruism explains cooperation/ prosocial behaviour?

people altering their behaviour when observed when reputation matters, cooperative people are chosen more often, and prosocial people benefit from their cooperation in form of partnership

How is competitive altruism (Roberts, 1998) different to the previous theories about prosocial behaviour?

previous theories focused on related individuals (kin selections, direct reciprocity (tit-for-tat), and indirect reciprocity (benefits from third party). But competitive altruism explains the kind of altruism people exhibit when they make donations

What is competitive altruism?

the idea that we are altruistic because when we are seen as prosocial, we are more attractive mates and friends which offer greater function (survival values)

What can we infer about competitive altruism if the 3 assumptions are met?

those who are seen as most cooperative can acquire the best partners, and competition of partners will increase in public cooperation