It is news to make women sick. Man-flu, the uniquely male condition that sees the sufferer bedridden by the most innocuous of illnesses, really does exist.
This means that they are not only more likely to catch diseases than women but also tend to suffer more seriously, and for longer, than their other halves.
Dr Olivier Restif and Dr William Amos applied a mathematical model to the various factors that characterise the genders.
They found that maintaining the ability to mate while ill was more important to men than getting better, yet for women it was the opposite.
Men also took the view that they would be reinfected quickly because their desire to compete with other males meant they were more likely to engage in risky activity. (© Daily Telegraph, London)