Psychology

Twin studies -50% of variance in aggression is down to genetics
Adoption studies - Miles and Carey adoptive boys and biological parents (criminal convictions)
The role of MAOA - regulates the metabolism of serotonin (Dutch family)

Value of animal research - knockout mouse model
Problems with assessing - self reports
Problems of sampling - focus' on individuals convicted of violent crimes

*small minority who regularly offend
*single offence not necessarily violent (THIS AFFECT THE VALIDITY)

Difficulties in determining the role of gene
*more than one gene contributes
*other influences e.g. Social
*factor are able to interact

Mother-son relationships
Brain sex theory
Phantom limb

Zucker - 64% compared to 34% who were sub clinical
Chung et al - BSTc doesn't develop until adulthood
2/3 Ftm, 2/3 non transsexual males, only 1/3 MtF

Division of labour
Mate choice
Cognitive style - E-S theory

Research methods - cultural bias
Speculative
Waynforth and Dunbar (looked for physical attractiveness 44% vs 22%) (portrayed as physically attractive 50% vs 34%)
Autism - reasons for males not being able to empathise

Strive to achieve fairness
Ratio of inputs and outputs

Hatfield - newlywed
Gender difference - proposes a gender bias
Clarke and Mills - colleagues and business partners
Real world applications

Voluntary/ non voluntary
Individual/ group based
The importance of love

Myers - no difference in marital satisfaction (USA and India)
Chinese study (1949 70%, 1990s 10%)
Voluntary not always successful
Cultural bias (IDA)
Increasing urbanisation

Low levels of seretonin (increased susceptibility) dexfenfluramine decreases seretonin and increases aggression
Increases in dopamine (amphetamines) antipsychotics decrease dopamine
Testosterone increases aggression (dabbs studied criminals)

IDA -gender bias
IDA - real world application
Evidence from the use of anti depressants
Evidence is inconclusive - couppis and Kennedy said it was a consequence rather than a cause as they seek out aggressive encounters as it is on a reward pathway.

Best possible partner they can attract without possible rejection (similar)
More social desirable (partner also) matched in terms of social desirability means happy relationship
Physical attractiveness means better other attributes 'halo effect'
Social attractiveness means status wealth popularity and a likelihood of them feeling similar

Walster et al -computer dance study (Minnesota 752(6 months later))
Places that you meet only judge on looks
Alternative view - reward need satisfaction
IDA -reductionist (simplifies) attention not paid to proximity = more rewarding