altruitate Flashcards
What is altruism?
Behaviour by an individual that increases the survival chance of another individual while decreasing the survival change of the actor.
What happens in terms of natural selection?
The donor incurs a reproductive cost (c) while recipient incurs a reproductive benefit (b).
Was Darwin wrong?
If evolution by natural selection is about maximising individual reproductive success, then no individual should sacrifice their life or reproductive potential for the benefit of another.
Darwin wasn’t wrong, he was incomplete. He didn’t know about genes. Natural selection is still a viable mechanism if we model it at the level of genes.
Between who does most altruism happen?
Most altruism happens between relatives
Relatives share a higher proportion of their genes than non-relatives.
If one views reproductive success in terms of the long term survival of genes, altruism does not contradict survival of the fittest.
What is Hamilton’s inclusive fitness theory and kin selection?
Fitness (reproductive success) should be measured in terms of the promotion of one’s genes including those copies we share with relatives
If we promote the survival of our kin (genetic relatives) we are also promoting our own long term genetic survival
What is direct and indirect reproductive success?
Direct - actual young an individual produces (Darwin’s theory)
Indirect - contribution to the survival and reproduction of copies of one’s genes contained in one’s relatives (Hamilton’s extension of Darwin’s theory)
What is Hamilton’s rule?
Altruism is favoured by natural selection when:
rB>C
R - relatedness (proportion of shared genes)
B- benefit to the recipient (how many more offspring are produced)
C- cost to the altruist
What about human kin selection?
Madesen (2007) showed that participants endured skiing posture longer in order to win money for themselves and close relatives than distant relatives or a charity.
What are the psychological benefits of altruism?
Making people keep track of their own kindness increases their happiness.
What is the neurobiology of altruism?
Similar brain regions are active when receiving a reward and making a donation.
Moll et al (2006) - human fronto-mesolimbic networks guide decisions about charitable donations
What is the role of the medial prefrontal cortex in altruistic behaviour?
Medial prefrontal cortex is involved in the emotional aspect of the footbridge scenario.
Medial prefrontal cortex is involved in altruistic behaviour.
Damage to the prefrontal cortex increases utilitarian moral judgements (saying yes to the footbridge dilemma - that they’d save 5 people at the cost of 1)
