Physiological Psychology

evolutionary psychology

intends to provide the framework for approaching all areas of psychology to provide a unfiying theory (to be a science). tries to understand ultimate (why) causes and root origins of human psychology, rather than just proximate (how) causes

niko tinbergen’s four questions for understanding a phenomenon

1. mechanism (causation)

2. ontogeny (development)

3. phylogeny (evolution)

4. function (adaptation)

evolution

descent with modification, i.e. change in trait frequency within a population over time

evolutionary processes of modification

mutation, migration, genetic drift, selection

principles of natural selection

1. organisms in an environment are theoretically capable of producing more offspring than the environment can sustainably support

2. there will be variation in how well suited some individuals are to their environment, affecting their chances of survival

3. some of the variation will be heritable

classifications of selection

directional selection, stabilising selection, disruptive selection

directional selection

favours an extreme version of a trait, happens when there is change in the environment and new selection pressures are present

stabilising selection

favours neither extreme but finds moderate traits preferential, happens when there needs to be balance in trade offs between options

disruptive selection

favours more than one extreme version of a trait over more moderate versions when both extremes have advantages that may compensate for any disadvantages. most common in highly diverse environments with different ways to access resources or when a species splits in migration to slightly different environments

fitness

an organisms ability to survive and reproduce, leaving its genes in the next generation

sexual dimorphism

when there are large differences between organisms in the same species

sexual selection

the idea that traits that aide in reproduction are beneficial even at the risk of individual survival

intrasexual selection

when members of the same sex compete directly with each other for access to mates

intersexual selection

when members of one sex choose members of the other sex