Biological and social learning theories of offending
Harry's actions could be explained by the biological theory of offending. This theory states that criminal behaviour is a result of biological factors, such as chromosomal makeup and genetics, and is a contribution to the 'nature' side of the 'nature'/'nurture' debate - such theorists believe that biology is the only factor that causes a person to commit a crime, as oppose to environmental factors.
Biological theories state that the chromosomal makeup of an individual causes criminality, therefore, there as been research into the criminal activity of those who possess an extra 'y' chromosome, and subsequently have exaggerated male characteristics. According to theory, the extra 'y' chromosome was suggested to lead to high testosterone levels, hightened aggression, and powerful body build - according to the theory, they should be involved in more crime. However, XYY males were not as predicted, and Graham et al found normal testosterone levels, as well as aggressive levels. XYY males are, however, rare in the general population, and over - represented in the offender population, which supports biological theory as Price et al found 28% of criminally insane males had XYY as oppose to the 1% of the general population. This suggests that it is this chromosomal makeup that encourages criminality, yet XYY males may be this way due to having to deal with the aspect of being different during adolesence, and hence, reverting to aggression and crime. It seems that people who are involved in crime due so due to many different factors, as crime as it is mentioned in the theory, is not a natural or homogenous category of behaviour.
In order to determine how much biology contributes to offending, family history and twin studies have been conducted. One such family study was conducted by Osbourne and West, who found that if the father had a criminal conviction, 40% of the sons do, whilst if the father doesn't, only 13% of sons do. This supports biological theory, yet, fathers and sons share the same environment, and this is a factor which could lead to crime concordance rates. Genetically exact twins have also been compared to 30% DNA twins, who all had criminal records. Crime concordanance rates were higher (77%) for MZ twins and lower (12%) for DZ twins, promoting the idea that genetic similarity makes it more likely for both twins to display criminal behaviour. This sample was small however, only involving 30 twins, and so cannot be generalised to the whole population. Twins are additionally raised in the same environment, and it could be this factor as oppose to the biological side, which causes crime. crime may also be due to social interactions, due to the fact that they look the same, which causes them to be treated similarity on a social level. Furthermore, more modern day experiments such as Christiansens study, only found a 35% MZ conconrdanace rate and 13% DZ rate, suggesting the generic influences may not be as strong as primarily conceived to…