Illness

Robert Brockway proposed an hypothesis on illness:

When men get ill they are typically sick longer but have fewer symptoms. Most symptoms of illness are actually part of the immune system's response to the invader.

In ancient times men would rove further from camp. A sick woman would be no more than a few hours from camp and could walk home to rest. A sick man could be days from camp. As a result, they needed the capacity to stay on their feet. If they became unable to move due to illness far from camp they would likely die.  Having a hunting party wait around for days while one man recovers from a virus would not be practical.

As a result, men evolved an immune response which resulted in fewer symptoms. The tradeoff is that men will remain sick for longer.  This seems to be borne out by data which shows that women take significantly more sick leave than men do, even after accounting for the need to look after children.