The role of hormones in explaining aggression

What hormones can cause aggression?

Low levels of cortisol, high levels of testosterone

Explain the role of testosterone in aggression

Observations show aggression is usually attributed to the effects of this male sex hormone. It is produced in the gonads and in small quantities by the adrenal glands in both sexes, but is found in much higher quantities in males.

Explain the role of cortisol in aggression

Cortisol is a hormone produced in the adrenal glands - its main job is managing stress levels. Cortisol seems to inhibit aggression.

What does the duel hormone hypothesis state?

That high levels of testosterone lead to aggressive behaviour only when levels of cortisol are low. When cortisol is high, testosterone’s influence on aggression is blocked.

Strength of the theory?

There is high level of control in studies. Motelica-Heino, Edwards and Roffi (1993) found that rodents which are castrated show no aggression. However, when they were given an injection of testosterone the aggression re-emerged. This is a strength because it shows a very simple cause and effect relationship between testosterone and aggression.

Weakness of the theory?

Low generalisability in studies using animals for research, such as Motelica-Heino, Edwards and Roffi (1993). This is because rodents don’t have the higher order thinking needed to control their aggression, so we can’t compare the findings to humans.

What did Dabbs et al (1995) find?

Measured testosterone in the saliva of 692 adult male prisoners. The study found higher levels of the hormone in rapists and violent offenders than burglars and thieves.

What did Dabbs et al (1988) find?

Tested testosterone levels in 84 female prisoners. Testosterone was highest in women who had cases of unprovoked violence, but lowest where violence was defensive (eg- in domestic abuse cases). This supports the idea that testosterone is correlated with aggression.

What did Pompa et al (2007) find?

Found that high levels of testosterone only caused high levels of aggression if low cortisol levels occurred.