SOME young men may be aggressive because they have a reduced ability to produce a hormone that restrains violent behaviour in stressful situations.
at the University of Cambridge and his colleagues pitted young, male volunteers against virtual rivals in a provocative, stressful and frustrating video game that carried a monetary prize.
As expected, levels of the stress hormone cortisol rose in control volunteers. But in boys with “conduct disorder” – characterised by verbal and physical aggression and cruelty – levels of cortisol actually fell (Biological Psychiatry, ). The levels were similar to those of unstressed boys, says Fairchild.…



