HORMONAL MECHANISMS Lesson three

Neural mechanisms How does the research support the N.M theory? Crockett et al (2008) carried out a repeated measures experiment on 20 participants. In both conditions the participants had fasted and were given a protein drink in the morning before taking part in the study. The difference in the drink was the difference in the conditions: one drink contained tryptophan, which the body needs to make serotonin; the other drink did not contain it. On both days that the study took place participants played the ultimatum game. In this game one player poses a way to split a sum of money with a partner. In the condition where the participants had had the drink that did not contain tryptophan (so their serotonin levels were low) they showed increased aggression toward offers they perceived to be unfair.

Davidson et al (2000) found that violent criminals had markedly lower levels of serotonin to non-violent criminals. Mann et al (1990), who manipulated levels of serotonin. They administered the drug dexfenfluramine known to deplete serotonin levels, to 35 healthy adults. They then used a questionnaire to assess hostility and aggression levels, and found these levels had increased among males after treatment with the drug. Potegal et al (1996) researched hamsters and found that stimulation of the corticomedial amygdala increases aggression and lesioning of this area reduces aggression in hamsters.

Wider Evaluation-Starter There are many studies that investigate the role of neural mechanisms in aggression which use animals and/or specific types of people (e.g. criminals). What potential problems could this pose? Use at least one Psychological term

Objectives Describe and evaluate the role of hormonal mechanisms in aggression Outline and evaluate research into testosterone and aggressive behaviour Identify the issues of gender bias and determinism in research

Starter- On boards As a spider diagram or a list… What do you know about hormonal mechanisms in relation to aggression?

Explanations High testosterone High testosterone/low serotonin Mismatch effect

Basic biological information on testosterone Predominately a male hormone however women do have testosterone just much lower levels. The hypothalamus and the pituitary gland in the brain control testosterone production. The hypothalamus instructs the pituitary gland on how much testosterone to produce. The P.G then sends messages to the testes (in males this is where most of the testosterone is produced) Testosterone is involved in producing the male sex organs as well as adult male features.

Mismatch theory An alternative theory is the mismatch effect. This effect also reflects the view that testosterone links to dominance, so the higher the testosterone you have, the more dominance or status you also want. According to the mismatch effect, testosterone only becomes important when there is a mismatch between the level of testosterone in the body and the status of the individual. If an individual has high status and high testosterone, no aggression will result, but high testosterone and low status, or low testosterone and high status, will result in aggression.

Mismatch theory Dominance Status Level of Testosterone Low High High low

Evidence in relation to hormonal mechanisms Kreuz & Rose (1972) BPS article Josephs et al (2006)

Kreuz and Rose (1972) Kreuz & Rose (1972) studied testosterone levels in a group of 21 young adult male prisoners and found a correlation between scores on psychological tests and testosterone. Their testosterone levels did not relate to whether they fought with others whilst in prison, but it did relate to the nature of the crimes they had committed. The 10 prisoners with histories of more violent crime such as assault and armed robbery did have statistically higher levels of testosterone than the 11 prisoners who had committed non-violent crimes. Questions: Ground this to the possible explanations for the role of testosterone on aggression Any concerns about the research method or sample?

Article Read the article from the BPS and answer the questions at the bottom of the sheet.

Josephs et al (2006) Josephs et al (2006) conducted an experiment using the saliva samples of participants and found that men and women high in testosterone levels reacted negatively after a loss of high status becoming stressed, confused, and anxious which is a state of mind that could lead to aggression. However, men and women with low levels of testosterone who were put into a position of high status showed the same pattern of upset which could also lead to aggression. Questions: Ground this to the possible explanations for the role of testosterone on aggression

Determinism (vs free will) Determinism sees human behaviour of a product of forces beyond the control of the individual. States that people have no control over their actions. Determinists would argue that internal and external forces control a persons behaviour. Two types of determinism are environmental determinism and biological determinism. This means behaviour should be predictable. Determinism is a scientific account of behaviour.

Strengths and weaknesses of taking a deterministic view S = Emphasis on cause and effect= make the world more understandable and predictable= could be worthwhile in trying to change certain things in society. S = Purpose and goal of science= make its more acceptable to society = scientific basis and objectivity. W = Does not allow for freewill, freewill is an illusion - we think we have choice. W = Can never fully explain behaviour because behaviour may be too complex.

Determinism How is this relevant? How does it link to hormonal mechanisms? (extn- Neural mechanisms?) Why is this a problem?

IDA (P) All explanations; serotonin, the role of the brain and testosterone: into aggression have also been criticised by psychologists for being deterministic. (E) All theories suggest that aggression is the result of neural and hormonal mechanisms- biological factors. All theories fail to consider the role of free will in that we have a choice in how we behave and thus fails to take into consideration individual differences shaped by situational factors. (C) With a lack of individual differences the theory fails to provide a good explanation into institutional aggression of all individuals. As a result the external reliability of all theories is weakened.

Evaluation of research (AO3) Many studies conducted looking into testosterone and aggression are based on correlational analysis or are natural experiments or have been conducted on animals. Why do you think the above causes problems? Comment on the validity of the supporting evidence. Concluding evaluation?

Case study A pharmaceutical company has introduced a new drug which suppresses testosterone and claims to lower the level of aggression in individuals. They are offering this treatment to the NHS and prison services for service users displaying aggressive behaviour. What moral and ethical issues does this raise?

Question- essay plan June 2011 Discuss the role of neural and/or hormonal mechanisms in aggression. (8 marks+ 16 marks) Bullet point / list a structure of this essay answer