TONY SOPRANO: And to think I’m the cause of it.
DR. MALFI: How are you the cause of it?
TONY SOPRANO: It’s in his blood, this miserable fucking existence. My rotten fucking putrid genes have infected my kid’s soul. That’s my gift to my son.
Studies have shown that male children who are severely maltreated are more prone to anti-social and violent behaviour in later life. Is this due to their parents passing on ‘bad’ genes, the child growing up in a ‘bad’ environment, or a combination of the two?
A study by Moffit et al looked at how children’s genes interacted with their environment to produce (or not to produce) later anti-social behaviour.
The study focused upon one particular group of genes known as MAOA genes (MAOA is an abbreviation for the brain chemical MONOAMINE OXIDASE A).
It was found that those with high activity MAOA genes were, in the main, protected from the potential adverse effects of the problematic environment in which they were brought up:
THEIR HIGH ACTIVITY MAOA GENES MADE THEM RESILIENT AGAINST ENVIRONMENTAL INFLUENCES WHICH CAN OTHERWISE LEAD TO AN ANTI-SOCIAL PERSONALITY.
The opposite was the case for those who had low activity MAOA genes:
THOSE WITH LOW ACTIVITY MAOA GENES WERE MUCH MORE LIKELY TO DEVELOP ANTI-SOCIAL BEHAVIOUR PATTERNS IF THEY WERE MALTREATED AS CHILDREN COMPARED TO THOSE WITH HIGH ACTIVITY MAOA GENES.
In the study, those in the second group (low activity MAOA genes) committed four times as many assaults, robberies and rapes.
WHAT CAN BE CONCLUDED FROM THIS?
It seems, therefore, that PARTICULARLY BAD OUTCOMES, IN TERMS OF PROPENSITY TO DEVELOP ANTI-SOCIAL BEHAVIOUR, are much more likely if the individual in question has had BOTH a ‘bad’ childhood environment AND has inherited ‘bad’ genes (low activity MAOA genes). Indeed, it would appear that the JOINT EFFECT of BOTH is GREATER THAN THE SUM OF THE PARTS of the two factors.
This finding has been confirmed by other studies showing that low activity MAOO genes are connected with the development of anti-social behaviour.
These findings have implications for treatment of psychological conditions associated with aggression as there are drugs which alter brain neurochemistry by acting upon monoamine oxidase. However, it should be noted that these drugs are not without risk and cannot always be guaranteed to be helpful. All treatment options require consultations with the relevant medical experts.
Fergusson DM, Boden JM, Horwood LJ, Miller AL, Kennedy MA. MAOA, abuse exposure and antisocial behaviour: 30-year longitudinal study. Br J Psychiatry. 2011;198(6):457-463. doi:10.1192/bjp.bp.110.086991
David Hosier BSc Hons; MSc; PGDE(FAHE).