Discuss genetic factors involved in agressive behaviour.

Genetic factors involved in aggressive behaviour have been shown through a number of various ways. The use of twin studies is useful in researching in to this field as if a greater similarity is shown in monozygotic twins (Mz, identical, share 100% DNA)than dyzygotic twins (Dz, non-identical, share 50% DNA) then it can be argued that nature overrides nurture in aggressive behaviour. McGuffin and Gottesman found a concordance rate of 87% for Mz twins for agression and anti-social behaviour compared to 72% in the Dz twins, which supports this idea. Also, Coccuro et al analysed 182 Mz twins and 118 Dz twins and found almost 50% of the variance in aggressive factors was down to genetic factors.