week 7- cooperation

cooperation

behaviour that increases the fitness of those involved

altruism

behaviour that benefits another indivudal but comes at a cost to yourself

therefore, indivudals must behave in ways that also improv own fitness

gene selection

genes are successful when they produce more copies of themselves

individual selection

indivudals are successful when they reproduce

the selfish gene theory

helping relatives can also benefit your own genes

inclusive fitness

indicudal evolutionary success includes nothing their own reproduction and the reproduction of genetically related indivudals

kin selection

helping relatives because they share some of your genes

Hamiltons rule

altruism if favoured when the cost to the indivudal is less than the benefit to the recipient x their relatedness

bending squirrels and altruism

males call less compared to females because their is less genetic relatedness

reciprocal altruism

cooperation where an indivudal helps another, expecting future returning of the favour

the prisoners dilemma

demonstrates conflict between cooperation and selfishness

two indicudals must decide wether to cooperate or betray

game theory

the study of interactions where one idnivudals best decision depends on another’s actions

prisoners dilemma options

• both cooperate (stay silent)- only one year

• both defect (expose) - two years

• one defect, one cooperate- defector receives best, cooperator receives worst

one shot prisoners dilemma

defection is dominant

iterated prisoners dilemma

indicudals interact repeatedly, making cooperation possible

tit for tat is a winning strategy

copies the partners previous action so it’s retaliatory and non-envious

evolutionarily stable strategies

a strategy which cannot be invaded by alternative strategies If all members adoptt it

considers- all c, all d and tit for tat

collective action

when an entire group contributes fairly and shares the benefits

collective action problems- free rider problem

indiuvdals can benefit from the groups efforts without contributing themselves

how to reduce free riding

• memory for dishonesty

• language to idenfity

• altruistic punishment

altruistic punishment

accepting a personal cost to punish someone behaving unfairly

prosocial emotions

emotions that encourage cooperation such as shame, guilt, fear of ostracism

the second order problem of altruistic punishment

punishers pay cost while non-punishers benefit without paying, then becoming free riders themselves

group selection

selfish indivudals tend to be more fit

but..

altruistic groups may be more successful