How important are genes?
There is a lot of theorising in the gene field as it is a relatively new field and involves expensive equipment with well trained technicians to read the images and results of the 2-3% of genes that have been identified so far. A number of studies have been carried out over the past decade to somehow discover whether the environment or our genetic hereditary history affect not only our mental illness but in particular our well-being and life satisfaction. Studying twins who are reared apart and comparing them to each other and to their siblings has helped to form an interesting picture.
A number of other studies seem to have found an approximately 50/50 influence of genetics and environment which links up with Lyubormirsky's empowering encouragement to take our life satisfaction into our own hands and change at least our 'brain environment' if not physical environment: our thought patterns and life habits.
Different versions of the same gene!
In studying gene variation it seems that we human beings have the same genes (polymorphism) but that there are different versions of the same genes known as alleles, which account for trait, behaviour and mental and physical illness variation. In a longitudinal study of children with behavioural problems a link between childhood maltreatment and subsequent anti-social behaviour with lower Monoamine oxidase A (MAOA) activity. MAOA is an enzyme involved in metabolising neurotransmitters in the brain, which seems to influence the vulnerability of a child to maltreatment, as children with high MAOA show greater resilience to maltreatment and abuse than children with low MAOA who seem to be negatively affected by maltreatment (Belsky et al, 2007).
Some children more vulnerable than others:
Belsky and colleagues (2009) however object to the idea of seeing children with low MAOA as pre-destined to become victims of their gene variation. They point out that in Caspi's research it could be noticed that children with low MAOA activity who had not been abused actually scored lowest in anti-social behaviour.
Similarly, women who had the highest amount of antisocial personality disorder symptoms were found to have low MAOA activity but also to have a history of being sexually abused while other women who had low MAOA activity showed the least amount of antisocial personality disorder symptoms when there was no history of abuse. It seems that people with this short allele version of gene show the fewest symptoms of antisocial behaviour when they experience a supportive home environment.