Aggression : Hormonal Mechanisms

Question 1

What is androgen?

Answer 1

A male sex hormone

Question 2

What are the effects of testosterone?

Answer 2

• Improved mood, confidence, inc sex drive, memory function
• Muscle growth, inc strength and endurance
• Inc bone mass density and maintenance
• Inc read blood cell production
• Sperm production, erectile function, prostate growth
• Hair growth, collagen growth

Question 3

What is testosterones role?

Answer 3

Testosterone regulates social behaviour via its influence of the brain implicated aggression. Daly & Wilson (1988) suggested aggression is highest in males 20+ yrs when testosterone peaks (males have generally more aggressive v females as they have more testosterone)

Question 4

How do steroids work?

Answer 4

Mimic testosterone, increasing muscle mass and strength but can also make people more aggressive.

Question 5

Animal evidence

Answer 5

Giammanco et al (2005) demonstrated experimental incs in testosterone are related to greater aggressive behaviour and the removal of the testes reduces aggression in many animal species.

Question 6

Prison evidence

Answer 6

Dolan et al (2001) found positive correlation between testosterone levels and aggression in sample of 60 male offenders in UK maximum security hospitals. The men mostly had personality disorders and history of impulsive (reactive) violent behaviour.

Question 7

Progesterone evidence

Answer 7

Levels of progesterone vary during ovulation and are lowest after menstruation. Ziomkiewick (2012) found negative correlation between progesterone levels and self-reported aggression.
Low levels of progesterone are linked to increased aggression in women.

Question 8

What are the strengths of hormonal mechanisms?

Answer 8

• ability to account for context dependent increases in aggressive behaviour (particularly following comical challenges or status losses → Mehta and Josephs (2006) measured Ps testosterone levels before and after a competitive game loss. After the loss, 73% of those with increased testosterone chose to re-challenge the winners (operationalised as aggression), compared to only 22% of those whose levels decreased. However, the study implies a narrow definition of aggression. Real-world aggression can be expressed in many ways, such as verbal aggression or physical confrontations, which may not be fully captured here.

Question 9

What are the limitations of hormonal mechanisms?

Answer 9

• explanation that inc testosterone levels lead to higher aggression may be incomplete → Carre and Mehta (2011) proposed the dual-hormone hypothesis, which suggests high testosterone only promotes aggression when cortisol levels are low. When cortisol is high, it appears to inhibit testosterone’s influence on aggression.