Women in countries ranked as less gender equal are more likely to choose traditionally male courses such as the sciences

We all know what is meant to happen when the genders become more equal. As women smash glass ceilings and open up education, other differences should disappear too.

Without the psychological shackles of being the second sex, women are free to think and behave as they want; to become physicists or chief executives, unfettered by outdated stereotypes.

Yet to the confusion of psychologists, we are seeing the reverse. The more gender equality in a country, the greater the difference in the way men and women think. It could be called the patriarchy paradox.

Two new studies have again demonstrated this counterintuitive result, meaning it is now one of the best-established findings in psychology, even if no one can properly explain it.

In a survey of