Men may have the ultimate excuse for being prickly under pressure - apparently it's all down to their genes.
Scientists think they have identified the "macho" gene that makes men more aggressive when under stress.
Experts say it could explain why men typically have a "fight or flight" response
while women try to defuse difficult situations, or "tend and befriend".
Australian researchers have proposed that the SRY gene - found only on the Y chromosome - and the proteins it activates in the body are to blame, after studying the chemicals secreted by men reacting to stress.
The gene was previously thought to be involved only in the development of male characteristics in the womb, but Dr Joohyung Lee and Professor Vincent Harley from Prince Henry's Institute in Melbourne have shown that its proteins are present in the brain and other organs of adult males.
