Sharing their bed with another person can reduce men's brainpower, scientists at the University of Vienna have found out.
When men spend the night in the same bed with someone else, their sleep patterns are disturbed. That leads to poorer performance in mental agility tests the next day, the team of Professor Gerhard Kloesch have said.
Women, however, do not suffer the same problem, the researchers said.
They had monitored eight unmarried, childless couples in their twenties, asking them to spend ten nights sleeping apart and ten together.