While no woman has been president of the United States  yet  the world does have several thousand years’ worth of experience with female leaders. And I have to acknowledge it: Their historical record puts men’s to shame.

A notable share of the great leaders in history have been women: Queen Hatshepsut and Cleopatra of Egypt, Empress Wu Zetian of China, Isabella of Castile, Queen Elizabeth I of England, Catherine the Great of Russia, and Maria Theresa of Austria. Granted, I’m neglecting the likes of Bloody Mary, but it’s still true that those women who climbed to power in monarchies had an astonishingly high success rate.

Research by political psychologists points to possible explanations. Scholars find that women, compared with men, tend to excel in consensus-building and certain other skills useful in leadership. If so, why have female political leaders been so much less impressive in the democratic era? Margaret Thatcher was a transformative figure, but women have been mediocre prime ministers or presidents in countries like Sri Lanka, India, Bangladesh, Pakistan, the Philippines and Indonesia. Often, they haven’t even addressed the urgent needs of women in those countries.

I have a pet theory about what’s going on.

In monarchies, women who rose to the top dealt mostly with a narrow elite, so they could prove themselves and get on with governing. But in democracies in the television age, female leaders also have to navigate public prejudices  and these make democratic politics far more challenging for a woman than for a man.