Hormones and Behaviour
What is testosterone?
Testosterone is mainly secreted in the testes of males and the ovaries of females. It is the main male sex hormone and linked with aggression.
Wagner and Beuving (1979)
Aim: To investigate the aggressive effects of testosterone Method: The researchers performed a laboratory experiment on rats whereby the independent variable was testosterone and this was manipulated via castration. The dependent variable was aggression and this was measured by counting bites and bite attacks. Results: Castration reduced aggression. Injections of testosterone restored aggression in castrated mice who were previously judged to be aggressive and who had lost their aggression due to castration. Conclusion: Testosterone has clear links with aggressive behaviour in mice.
Shamay-Tsoory et al. (2009)
Aim: To investigate the negative effects of oxytocin Method: 56 participants were either given nasal doses of oxytocin or a placebo. They played a game of chance with another (fake) participant who either won more money ( jealousy manipulation), lost more money ('schadenfreude' manipulation), or won/lost equal amounts of money. Results: In comparison with the placebo, oxytocin increased the jealousy ratings when the (fake) participant won more money. Oxytocin also increased the ratings of 'schadenfreude' (enjoyment over other's misfortune) when the (fake) participant lost more money. However, oxytocin appeared to have no effect on the emotional ratings following equal monetary gains nor did it affect general mood ratings. Conclusions: This study shows oxytocin is involved in increasing envy and 'schadenfreude' and not just positive pro-social behaviours.
Guastella et al. (2008)
Aim: To investigate the positive effects of oxytocin Method: Oxytocin or a placebo was given to 69 healthy human male volunteers. They were then shown 36 happy, angry, or neutral human faces. Participants returned the following day to make 'remember' and 'know' judgements for a mixture of 72 new and the previously seen faces. Results: Participants given oxytocin were more likely to make 'remember' and 'know' judgements for previously seen happy faces compared with angry and neutral human faces. In contrast, oxytocin did not influence judgements for faces that had not been seen previously. Conclusions: This study shows that giving oxytocin to male humans enhances the encoding of positive social information to make it more memorable.
What is a Hormone and its function?
Hormones are the body's chemical messengers and are part of the endocrine system. Endocrine glands make hormones, which travel through the bloodstream to tissues and organs, and control most of our body's major systems
What is oxytocin?
Oxytocin is a hormone that is produced by the hypothalamus after being stimulated by the pituitary gland. If oxytocin is given to healthy individuals it seems there is an increase in trust and generosity.
