Role of Hormones in Human Behaviour Flashcards
Define Hormones
Chemical substances that circulate in the bloodstream and only affect target organs. Produced by glands in large quantities and disappear quickly.
Hormones and Aggression
Endocrine glands create hormones and secrete them into bloodstream.
Adrenal glands secrete adrenaline and noradrenaline which affect cells in organs and have a role in flight or flight, increase heart rate, helping to fuel aggressive response that could be needed.
Role of Testosterone
Males generally more aggressive than females.
Testosterone plays a role in regulating social behaviour through its influence on areas of the brain implicated in aggression.
Animal Studies of Testosterone
Demonstrated that experimental increases in testosterone are related to more aggressive behaviour in the males of several species.
Reductions in aggression accompany a decrease in testosterone as a result of castration.
Human Studies of Testosterone
In prison populations, Dolan et al found a positive correlation between T levels and aggressive behaviours in a sample of 60 male offenders in UK max security hospitals. Most of the men had personality disorders and history of impulsive violent behaviour.
Dual-Hormone Hypothesis
Not just one hormone causes aggression.
Cortisol is secreted by the adrenal glands to help body deal with stress, suggesting an interaction between the systems responsible for regulating aggression and stress response.
Dual-Hormone Hypothesis Study
Carre and Mehta claim high levels of T lead to aggressive behaviour only when cortisol is low.
When C is high, T’s influence on aggression is blocked.
Pompa et al found this exact association in adolescent males in relation to direct physical aggression.
Combined activity of T and C may be a better predictor of human aggression than either hormone alone.
Female Aggression
Although T levels in females are lower, aggressive behaviour can still be enhanced.
Eisenegger found that women given a dose of T behaved more generously and sociably in a lab based negotiating game.
The T->Aggression link seems to be more complex in females suggesting non-bio factors like gender roles may be important.
Research Support
Dabbs and Hargrove measured T in saliva of 87 female inmates of a maximum security prison. Found that degree of criminal violence was positively correlated with T levels.
T was also correlated with extent of women’s aggressive dominance in the prison.
Aggression-T link so often found in male prisoners was replicated, increasing validity of association.
Competing
Studies of hormonal influences on human aggression are correlational, although it is ethical and practical, we can’t establish a casual relationship. Elevated T may be outcome of aggression or a result of another hormone change.
Weakness
Difficult to determine T levels as it is complex.
Psychologists determine between baseline and fluctuating T.
Carre et al argues that baseline T is less important to human aggression than it is in animals.
Meaning that baseline used in many studies may not provide a valid indicator of T level in relation to aggression.
Applicability
Understanding the effects of hormones on aggression can lead to practical benefits.
If aggression is chemically controlled it should be possible to manufacture a drug that influences the hormonal mechanism and reduces aggressive behaviour.
A study found that a testosterone-lowering drug called Depo-provera reduced sexually aggressive behaviour in some offenders.
Anti-T drugs could have a positive effect for whole societies.
