Hormone AO1

• Testosterone

  • Testosterone is an androgen (a male sex hormone) secreted by the testes in males and to a lesser degree by the ovaries in females. Males have about 8x more testosterone than females.
  • It is essential for physical health and well-being and for reproductive growth and development if male secondary sex characteristics such as beard growth and deep voice.
  • Experiments with animals have consistently demonstrated a link between testosterone and aggression.
• Testosterone

  • Wagner et al (1979) observed reduced levels of aggression in male mice following castration. In addition they were able to return aggression to pre-castration with injections of testosterone.
  • Testosterone is one of the androgen hormones, so called because they produce male characteristics ( which is why aggression is often seen as more of a male characteristic). Levels of testosterone reach a peak in young adult males and typically these levels gradually decline with age
• Cortisol

  • Cortisol appears to have an important mediating influence on other aggression-related hormones such as testosterone, by inhibiting the likelihood of aggressive behaviour.
  • Popma et al ( 2006) found positive correlation between testosterone and aggression, but only in participants with low cortisol levels