R5: Human Aggression + Brain & Genes

Question 0

Genes to brain

Answer 0

• impairments in pfc and other brain regions found in some ppl exhibiting anti-social behaviour not explained by environmental factors
• structural brain imaging combined with twin study’s demonstrate that genes explain a 90% variation in grey matter.

Question 1

MAOA gene in mice

Answer 1

• if neutralized, they become highly aggressive, if re-activated, they return to normal behaviour
• some replicability in humans

Question 2

Brain to behaviour

Answer 2

• not directly, brain only biases. E.g. Amygdala is centrally involved in fear conditioning, poor fear conditioning may result in a failure to fully develop conscience and thus less likely to be inhibited about anti-social behaviour

Question 3

Environmental influences on gene, brain, behavior pathway

Answer 3

• Early developmental experiences influence gene expression I.e. rats separated from mother for first 3 weeks more fearless and lower stress response in adulthood.
• social situations interact with biological factors

Question 4

Treating biologically based aggression

Answer 4

• early nutrition as prevention, first 3 yrs of life

- nt interventions include increasing serotonin with ssri’s