Genetics

Genetics

1. Genetics don't directly cause aggression, they influence elements of our biology.

2. Heritability: The extent to which genetic individual differences contribute to individual differences in observed behaviour.

3. Genetic Manipulation: The manipulation or alteration of the structure of genetic material in a living organism using recombination of DNA to produce specific results.

4. Monoamine oxidase A (MAOA) is found on the X chromosome. There are two types of MAOA; MAOA-L and MOAO-H

   • MAOA-L is associated with aggression because there isn't enough of the enzyme to get rid of the excess neurotransmitters associated with aggression (dopamine and serotonin) in the brain
     • Build up of serotonin and dopamine cab cause people to respond to stress aggressively.

5. MAOA gene regualates the MAOA enzyme to remove excess neurotransmitters associated with aggression therefore reducing aggression.

6. Supporting Study: Tuner 2007

   • Findings: Aggression is a moderately heritable trait, passed onto offspring

7. Supporting Study: Mattson 2003

   • Male mice who were MAOA deficient were quick to attack an intruder.

8. Human Supporting Study: Bruner 1993

   • Dutch Family with history of extreme violence in males. -MAOA mutation found on X chromosome (leading to low levels of MAOA. Conclusion: Excess neurotransmitters seem to predispose men to violence when under stress.

9. Supporting Study - Capsi et al 2002: Findings: Maltreated and abused men with low MAOA activity accounted for 44% of convictions. MOAO-L gene variant had no effect on it' own, only in circumstances of abuse as children. However, abused men carrying geneotype were 3x more likely to commit violent crimes.

10. IDA: Reductionist, Nature vs Nurture, Animal Research, Bioloigical