THE ROLE OF NEURAL AND HORMONAL MECHANISMS IN AGGRESSION - A new study which collected data on brain function while participants were watching violent videos has found that teenagers become desensitised to aggression over time. The researchers argue that violence on TV promotes aggressive attitudes and behaviour.

An interesting piece of research has shown that there are marked sex differences in the ability to read facial expressions while under stress. This may be another factor in explaining why men are more likely to get into fights than women.

There is much research that shows that playing violent video games like Halo: Reach and Grand Theft Auto increases a person's aggression. New research is now showing that this potential for aggression can last as long as 24 hours.

Last December we reported on a study that showed that testosterone does not cause aggressive behaviour, but is instead linked to status enhancing behaviour (which can involve behaving more fairly). Now a new study has shown that company bosses with high testosterone levels are more likely to behave aggressively in "Mergers & Acquisitions" negotiations.