Biochemical theories

• Males :

  Over production of testosterone is linked with crimes like rape and murder , levels peak between puberty and early 20's - this correlates with male crime rates.

  strengths :

  • There is strong medical evidence to support that substances and hormone levels can affect mood, judgement and aggression's.

  Weaknesses:

  • Often use studies of convicted criminals. Not representative of all criminal behaviour. What about criminals who don’t get caught, or minor crimes.
  • male bias and the effects are often overstated
• Females:

  Post natal depression and lactation have been used as partial defence for crimes like infanticide and shop-lifting.

  strengths:

  • There is strong medical evidence to support that substances and hormone levels can affect mood, judgement and aggression's.
  • Biochemical factors are recognised by the courts and in some case written into laws (For example infanticide).

  weaknesses:

  • sample size isn't big , many contradictions as lots of people in prison don’t have a medical reason.
• substance abuse :

  abuse of cocaine , heroin , crack and steroids correlate with violence and aggression particularly in the come down.

  strengths:

  • There is strong medical evidence to support that substances and hormone levels can affect mood, judgement and aggression.

  weaknesses:

  • May need an environmental trigger
• deficiencies in diet (vitamin B) :

  vitamin B deficiency links to erratic and aggressive behaviour

  strengths:

  • There is strong medical evidence to support that substances and hormone levels can affect mood, judgement and aggression.

  weaknesses:

  • What counts as a crime varies between time, place and culture. So it makes no sense to look for universal explanations, (that apply to all people in all contexts) as biological explanation do.