Hormonal Mechanisms in Aggression

Nota:

• Male sex hormone thought to influence aggression due to it’s effects on brain areas involved in controlling aggression.

1. Dabbs et al

   Nota:

   • Supportive. Measured salivary testosterone levels in violent & non-violent criminals.
   • Highest=history of primarily violent crimes. Lower=non-violent crimes.
2. Lindman et al

   Nota:

   • Supportive. Young males behaved aggressively when drunk had higher testosterone levels than those who didn't
3. Wingfield et al

   Nota:

   • Proposes that in monogamous species, testosterone should only rise above baselines breeding level in response to social challenges e.g. threats to status. Thus, testosterone surges is expected with a consequent rise in aggression.
   • Social cues

1. Archer

   Nota:

   • Supportive. Meta-analysis. 230 males over 5 studies 
   • Found a low, but positive correlation between testosterone and aggression. However, type of Pps, and form and measurments of agression differed substantially between studies.
   • Correlational data only shows causal data, but not why.
2. Albert et al

   Nota:

   • Refutive. Studies have found a link between testosterone and aggression, but others haven’t. Thus, there is inconsistent evidence.

Nota:

• Has a mediating effect on other aggression-related hormones like testosterone, possibly as it raises anxiety and liklelihood of social withdrawel.
• Low cortisol plays an important role by raising likelihood of aggressive behaviour.

1. Virkkunen

   Nota:

   • Reported low levels of cortisol in habitual violent offenders
   1. Tennes &Kreye

      Nota:

      • Low levels of cortisol in violent schoolchildren.

1. Four year study on boys with behavioural issues.

   Nota:

   • Supportive of the moderating effect of cortisol on aggressive behaviour.
   • Boys with consistently low cortisol levels began anti-social behaviour at a younger age, plus exhibited 3 times aggressive symptoms than boys with higher cortisol.
   • Thus, cortisol is ‘strongly and inversly related to aggressive conduct disorder’.

1. Gender Bias

   Nota:

   • Research suggests a link between testosterone and aggression higher for females.  Females may also respond to challenging situations with increased testosterone, displaying aggression
2. Reductionism & Biological Mechanisms

   Nota:

   • The links between biological mechanisms like testosterone with aggression isn’t as well established in humans. Complexity of human social behaviour means a biological explanation for aggression is insufficient on it’s own to explain all aspects of aggressive behaviour.