1. Hormones and Aggression

3. Essentially the argument is
Neural
Brain abnormalities
Hormonal
High levels of testosterone
..... are associated with aggression

4. Hormones & aggression Hormones & agrression What is a hormone?
A hormone is a chemical produced by the body that sends messages to organs of the body via the bloodstream.
Hormones are produced in glands, which are part of the endocrine system.
What is the role of testosterone in the body?
Testosterone is a male sex hormone produced in the testes and secreted by the adrenal gland which is needed to produce sperm.
Testosterone is also involved in the development of the male reproductive organs and produces male features, such as facial hair and a deep voice.
It is also said to be involved in aggression.

5. Aggression in animals
Using your textbook:
Define castration

6. Hormones and Aggression - Testosterone
Beeman (1947) and Wagner et al (1979) castrated male mice and found that aggressiveness reduced.
He later injected the mice with testosterone which re-established their aggressiveness.
Castration has since been used as a method for making domestic and farm animals more manageable.

7. Aggression in humans
Using the following slide answer the following questions: 1. How can testosterone levels be measured? 2. What are correlation studies?

8. Aggression in humans
Psychologists can take blood from humans to see what levels of testosterone they have and compare this to how aggressive they feel or act.
Some correlation studies (studies that see if there is a link between 2 variables) have found a relationship between high testosterone levels and questionnaire results showing greater reported aggression.
It is not certain though whether testosterone causes increased aggression or aggression causes increased testosterone

9. Testosterone is also clearly related to aggression in humans.
Dabbs et al (1987) – salivary testosterone levels were able to differentiate between 89 violent and non-violent criminals. The more testosterone the more violent their crime.
Dabbs et al (1995) – measured testosterone in saliva of 692 adult male prisoners. Found higher levels in rapists and violent offenders than in burglars and thieves.
Dabbs et al (1996) – looked at 12 fraternities (a social club for male undergraduates) in 2 universities. Members of fraternities with highest levels of testosterone were described as boisterous and macho, those with lowest were attentive and helpful.
Those frat boys at it again…

10. Gender and Testosterone
Dutch psychologist Stephanie VanGoozen & colleagues (1995, 1997) studied people undergoing sex change operations:
Women changing to men got testosterone injections – became more aggressive and sexual
Men changing to women got testosterone suppressants – became less aggressive and sexual

11. The same effects of testosterone are also found in women.
Dabbs et al (1988) – female prisoners. Testosterone highest in cases of unprovoked violence but lowest where violence was defensive (eg. In domestic abuse cases)
Other research has found conflicting results, but this is to do with the operationalisation of ‘aggression’.

12. Recap
 In almost every culture, males are far more aggressive than females;
could this be because of testosterone (male sex hormone)
 Testosterone is secreted by the adrenal glands and testes and is needed
to produce sperm, develop the male reproductive system and produce
male features e.g. facial hair, deep voice etc.
 Women also have testosterone but males produce more of it (10 times more!)
 Animal research has shown that injecting testosterone increases levels of aggression whilst removing the testes decreases levels of aggression.
 Castrating a male animal lowers its testosterone level making it less aggressive.
 If that animal is then injected with testosterone its aggression level is restored to normal.
 This is strong evidence that testosterone is responsible for aggression.
 Can we say the same about humans? It is unethical to deliberately increase the testosterone level in men.
 Psychologists can take blood from humans to see what level of testosterone they have and compare it to how aggressive they feel or act. Some correlation studies have found a relationship between high testosterone levels and questionnaire results showing greater reported aggression. However, it is not certain whether testosterone causes increased aggression or aggression causes increased testosterone.

13. Hormones and Aggression

14. Lets’ Start with A01
Hormones Testosterone Endocrine System Castration How can testosterone levels be tested? Please get your handout that I set for h/w out.

15. Task 1 : For each of the following statements, decide whether it is true or false.
1. In animals, there is no clear cause and effect relationship between testosterone and aggression.
2. Human studies show a relationship between aggression and testosterone in correlation studies.
3. All humans with high testosterone levels are aggressive.
4. Correlation and animal studies have weaknesses. Animal studies may not apply to humans, and correlation studies just look for relationships and are not direct evidence.
5. If testosterone is the cause of aggressive behaviour, are all men more violent than women?
6. This explanation of aggression completely ignores the huge impact of upbringing and social circumstances on our behaviour.

16. Task 2: for each of the following statements, identify whether it is a strength or a weakness for evaluating the link between biology and aggression:
1. Animal studies that have involved damage to or removal of the amygdala offer evidence for its link with aggression.
2. Studying the human brain is difficult and can be very risky, so there is no way of making sure areas of the brain are linked to aggression.
3. Animals and humans are different in many ways, so animal research suggesting a link between the brain and aggression may not be applicable to humans.
4. The case study of Charles Whitman (1966) are evidence for its link with aggression in humans.
5. Case studies are unreliable, as the reason for an individual’s aggression may be unique to that individual.
6. Aggression could equally be explained by the way children copy the media.

17. Task: Evaluate the role of hormones on aggressive behaviour (12 marks)
Strengths
Weaknesses

18. Evaluate the role of hormones on aggressive behaviour (12 marks)

19. Point – A strength of the argument that hormones are associated with aggression come from animal studies. For example…
Evidence-
Comment – Therefore this suggest that testosterone has a large role to play when explaining aggression.
Point – However, on the other hand….