week 8- competition

dominance hierarchies in animals

determine access to resources and determined by threats of force

transitivity

A hierarchy is transitive when relationships follow a consistent order

neural underpinnings of dominance

serotonin

why do dominance hierarchies exist?

doesn’t benefit groups but indivudals

e.g. dominant invdivsals gain access to resources

e.g. subordinate indivudal avoid fight it would probably lose

testosterone

social status hormone and increases when status is achieved

hawk dove game

models competition between two indviduals

hawk- aggressively competes for entire resource

dove- avoids fighting and behaves less aggressively

what is the best strategy in dove-hawk game?

there isn’t one

frequency dependent selection

occurs when the fitness of a behavioural strategy depends on how common it is within a population.

Positive frequency-dependent selection

• A strategy becomes more successful as it becomes more common.

• e.g. tit for tat

Negative frequency-dependent selection

• A strategy becomes less successful as it becomes more common.

• e.g. hawk dove strategy- being the only dove among many Hawks can be beneficial because you avoid costly fights.

young male syndrome

• Young men are disproportionately involved in killing other young men.

• There is also an increase in young male victims of homicide.

why does aggression happen

1. Resource acquisition: Aggression may be used to obtain resources.

2. Status acquisition: Aggression may be used to establish or defend social status.

warfare as an evolved adaption

• archaeological efidence

• Male chimpanzees form raiding parties that enter neighbouring territories and kill other chimpanzees.

• ‘the fierce people’ live under chronic warfare because they acquire more women

• gang members have more sexual partners

arguments against evolved war genes

1.Warfare requires collective action

• Successful warfare depends on individuals cooperating and making contributions.

• Individuals who make large sacrifices (heroes) may be disadvantaged compared with free riders.

• Free riders could benefit from others' efforts without taking the same risks.

2. Modern warfare differs from ancestral conditions

• Major modern wars do not resemble the small-scale conflicts that may have occurred in the Environment of Evolutionary Adaptedness (EEA).

• Yet people still choose to participate in modern wars.