genetic influence

• the basic difference between men and women is their genotype
• most people have 23 pairs of chromosomes. one pair of chromosomes decides whether we are male (XY) or female (XX). the genetic causes of aggression could lie in the Y chromosome. some individuals have a XYY genotype. these individuals were often refered to as 'super males' as they possessed two male Y chromosomes
• Court-Brown (1965) discovered 314 patients that had the XYY chromosomes and he put forward the view that these patients should remain hospitalized given their increased likelihood of aggressive behaviour.  
• Psychologists have used selective breeding in animals and have found that aggression is a trait that can be transmitted from parent to offspring – this supports the genetic explanation. 
• Twin studies have looked at aggression in MZ and DZ twins. Differences in rates of aggression between the sets of twins have indicated that aggression has a genetic element. 
• The MAOA gene is responsible for the production of a protein that allows the metabolizing of adrenaline, serotonin and dopamine. This means that neurotransmitters aren’t metabolised. 
• If adrenaline isn’t metabolised we end up with too much adrenaline which can cause hypersensitivity and overreacting to an external stimulus or to perceive a threat when one does not exist.  
• If dopamine isn’t broken down, increased levels are linked to aggressive behaviour. 
• Serotonin has a calming influence and low levels have been implicated in a reduction of control over impulsive behaviour.  
• A lot of research conducted is socially sensitive research.  

  Socially sensitive research – potential social consequences for the participants or the group of people represented by the research.