Hormonal influence

What is testosterone

A hormone

What does testosterone produce

Male characteristics eg Aggression

Sapolsky

removing the source of testosterone in various species typically leads to significantly lower aggression levels, and then injecting synthetic testosterone to increase its levels back to normal led to the aggressive behaviour returning.

Archer

men are usally more aggressive than women

Dabbs

Men have a much higher concentration of testosterone than women

Salivary testosterone measured in violent and non-violent criminals. Highest testosterone levels = history of mostly violent crimes; Lowest testosterone levels = only non-violent crimes.

Daly and Wilson

Ages 21-35 = highest testosterone concentrations and increase male-on-male aggression

Carre and Olmstead

Testosterone levels fluctuate rapidly to respond to the social environment

Evidence that shows a positive relationships between testosterone and aggression is inconsistent

Albert et al. (1994) reported positive correlations between testosterone levels and self-reported levels of aggression among prison inmates.

Olweus et al (1988) found positive correlations between testosterone levels and the likelihood of responding aggressively when provoked.

However, no correlation was found between testosterone levels and actual violent behaviour among male prison inmates.

THEREFORE, the relationship between testosterone and aggression in humans isn’t clear.

Aggression or dominance ?

Mazur (1985): it’s important to distinguish between aggression (intending to inflict injury) and dominance (wishing to achieve/maintain status over someone).

Aggression is a form of dominance (but dominance comes in many forms).

In non-human animals, testosterone influences dominance and this can be shown through aggressive behaviour.

However, in humans, this is more likely to be shown in a more varied and subtle way, e.g. status-striving behaviour.