Biological

• Serotonin

  Some studies show that levels of serotonin are linked with higher aggression. Serotonin is a neurotransmitter that controls a persons mood. Anti-depressants work by stopping the re-uptake of serotonin thus making a person feel happier. Control of serotonin levels by diet is possible as some foods including dark chocolate, cheese, nuts and salmon can help raise serotonin levels.
• Sterilisation

  Sterilisation prevents someone from further having children. This relates to biological theories linking genetics to criminal behaviour. This prevents it being inherited and passed on to the next generation.
• The death penalty

  The death penalty is the most extreme biologically driven policy. It is the idea that people inherit criminal behaviour - people can’t change. By ending someone’s life, it will prevent them from participating in criminality and may provide a deterrent for others.