Neural and hormonal mechanisms involved in aggression

• low levels of serotonin associated with aggression

Mann et al found increased hostility and aggression scores when serotonin depleted in 35 healthy subjects.

Unethical: subjects were healthy and mental health disrupted

Questionnaire: social desirability, how truthful were responses. females may be less likely to reveal true aggression, as deemed unladylike in society.

• increased dopamine= increased aggression.

meta ananlysis 0f 29 studies(Scerbo&Raine) consistently found low serotonin in  aggressive individuals compared to no significant rise or fall in dopamine levels.

Suggests serotonin is key neurotransmitter involved in regulating aggression levels.

• testosterone (esecially in males) influences aggression due to acting on brain areas involved in controlling aggression

• High levels of testosterone associated with dominace behaviour which occassionally manifests itself as aggression. (Human displays of aggression more subtle take form of assertiveness or competitiveness etc.)

• Basal model states testosterone causes change in preson's dominance. Whilst reciprocal model aggrees that testosterone levels vary with dominance. Proposing levels of testosterone are effect of dominance.

• Support from Dabbs et al who found criminals with high testosterone had high levels of violent crimes compared to those with low levels.

Sample: unrepresentative, criminals (biased) yet findings from non criminal population found similar results. lindman et al found aggressive drunks had high testosterone levels.

Temporal validity: although in 1987, tests biological elements therefore unlikely to change giving it temopral validity

• Support from Klinesmith et al (2006) found exposure to aggressive que increases testosterone. Males exposed to gun had increases testosterone and aggression than those exposed to child's toy.

Sample Bias: Male students not representative.

Gender biased: males differ from females physiologically.

Cause and effect: Does biology alter behaviour, or other way round?

Correlation?: Most research can only offer association between biological factors and aggression. Cause and effect cannot be established.

(I) Biological approach

(J) Aggresssion product of biological factors e.g neurotransmitters and hormones

(I/A) Aids understanding of behaviour by examining how the body works. If neurotransmitters found to significantly affect aggression, medicate can be given to severly aggressive individuals to reduce this.

If testosterone soley attributed to aggression this may result in males feeling their aggression is something they cannot control thus excusing violent tendencies.

(I) SSR

(J) Ethical concerns identifying males as predisposed towards aggression.Raise social concequences

(I/A) Care taken how results are presented/published

(I) Culture Bias

(J) Most research conducted in western societies. Not representative of other cultures where aggression may be viewed differently

(I/A) Subject to cultural bias. Although research may help us understand and control aggression in western societies the findings cannot be presented as universal. 

(I) Determinist

(J) aggression result of neural or hormonal mechanisms

(I/A) ignores free-will

(I) Reductionist

(J) link between serotonin and aggression and testosterone are more explicit in animals but humans are more complex and react with different stimuli from external environment that affect aggressive behaviour.

(I/A) Biological explanation alone insufficient to explain aggression in humans as human social behaviour is so complex and influenced by a variety of factors both internal and external.