Evolutionary explanations of aggression

1) Selection of the 'fittest male': males compete for females( intra-sexual selection), thus inclined to show displays of strength which derives from dominant behaviour (aggression)   Indulging in aggressive acts displays strength and shows female male can protect her.

2)Survival of young: E.g female dog attacks stranger if her cub's life appears to be threatened.

• sexual jealousy proposed to be natural selection mechanism to defer partner from sexual infidelity so as to prevent loss of resources.

• Occurs mostly in men, as it reduces risk of cuckoldry. Female sexually unfaithful may result in male providing for offspring not his own. So to ensure continuation of genetic line, must prevent sexual infidelity.

Cascardi & Vivian found jealousy most frequently attributed cause of anger and aggression.

• men guard against partner's infidelity either by conferring benefits or inflicting costs (violence). As not all men possess resources providing benefits some resort to using violence or threat of violence as retention strategy.

• Uxoricide= men killing female partners

• Young females still fertile, so killing wife ensures no other man gains in reproductive stakes. Her failure to commit sexual infidelity means his sense of reproductive fitness is in tact. (Aim is to continue genetic line)

Shackleford et al found that of 13670 homicides younger women had greater risk of uxoricide

• Shackleford et al (2005) found men's  retention techniques positively correlated with violence scores. Emotional manipulation prominent predictor of future violence.

• Females reported men using vigilance and emotional manipulation most likely to be violent to them.

Surveys: Self- report, answers may not be truthful as this is sensitive area. Social desirability?

Temporal validity: 2005 reflects relationships of today.

Cause and effect: Correlational, cause and effect cannot be assumed. Link between retention techniques and outcome can be assumed.

App: Tactics of mate retention early indicator of violence. Identifying what precedes violence can help us prevent it.  reduce domestic violence

(I) Evolutionary Approach

(J) Aggression a product of how human brain has evolved.

(I/A) Examines primary rather than immediate cause of aggression. Sees behaviour innate rather than by-product of stimulus from environment. Help reduce domestic violence.

(I) Determinst

(J) aggression result of how we have evolved to best survive.

(I/A) Ignores individual differences. Doesn't explain why some act differently. Obviously not everyone commits uxoricide, therefore there must be free-will.

(I) Reductionist

(J) reduces complex behaviour to mere adaptive mechanisms.

(I/A) ignores social factors such as norms and rules, and role of learning that constitute towards aggression.(social learning theory)

(I) SSR

(J) emotionally charged 

(I/A) Take care when publishing findings. Be sure to protect Pp's by ensuring anonymity.

(I) Ethnocentric

(J) research conducted in west yet findings presented as universal.

(I/A) Cannot explain cultural differences. Aggression viewed positively in some cultures e.g yanamamo of south america who gain status from male violence.