Biological Key Question

What are the implication for psychology if aggression is found to be caused by nature and not nurture?

Aggression is a universal type of behaviour found in all human societies to some degree or another. Aggression leads to violence, which can be defined as ' the intentional use of physical force or power, threatened or acrual, against oneself, another person or against a group or community'. This is physical aggression. However, there is also relational (or social) aggression which includes gossiping and name-calling. According to the medical journal 'The Lancet (2013)', there are 1.28 million deaths due to violence in the world each year:

• 842,000 due to suicide
• 405,000 due to homicide
• 31,000 due to war

For each death due to violence, there are dozens of hospitalisations, hundreds of emergency room visits and thousands of doctors appointments. More than this, violence can have lifelong consequences for physical health and mental health (trauma). It can slow economic development by making people too injured or frightened to work, as well as destroying property. Gun and knife crime costs the NHS £3 million a year. The Global Peace Index shows that violence is not evenly spread out; some parts of the world are much more violent than others. Sometimes there is a huge drop in violence the moment you cross the border (like going from the USA to Canada). This suggests that violence can be influenced by nurture and violence can be reduced by changing the law, the Government and people's attitudes. 

If we accept Darwin's Theory of Evolution, them we would expect the animals that are closest to humans in evolutionary terms to resemble humans in their behaviour. The discovery that chimpanzees engage in organised violence suggests that humans and chimps have both evolved these behaviours before their species diverged 6 million years ago. Humans and chimps have similar brains, including the amygdala that regulates aggression. If violence is not part of human nature, you would expect other animals related to us to be non-violent. If violence is caused by social pressures (like poverty and oppersion), then you would expect other animals like us would become violent when they were put under pressure (e.g by loggers). The solution to violence would be to improve the environment people live in, like by cleaning up cities, improving policing, creating jobs and building schools. However, if violence is part of human nature, none of these things will work and there will always by violence.

Cases (1995) used genetic engineering to breed mice with the MAOA-L mutation. The mice pups were much more fearful than normal mice but grew up to be much more aggressive. This MAO-A is linked to the 'fight or flight' response and that adult aggression is linked to finding the world a scarier place than it actually is. The MAOA-L mutation is suposedly present in 1/3 males. The important thing about genetic expalations like tis is that genes only give us predispositions or tendencies. If you have the 'warrior gene', you won't automatically grow up to be violent; you could compete in sport or be a police officer, using the aggression in other ways. Education is important here. Boys with the MAOA-L gene could be identified early and given more help with problem-solving, personal skills and career advice. CBT works by getting people to recognise their faulty ways of thinking and Freud's psychoanalysis helps people overcome the fear and aggression in their childhoods.