Women in science
If we look at the graduate students and postdoc fellows around, it is easy to tell that more than half are female in the science field. However, the truth is the leaders of labs in academy or related companies usually have fewer women than men. The imbalance of the women in science and those who succeed in science as a career reflects the reality that women have less advantage in competition with men in science.
In my point of view, there are some reasons that lead to this common, but not reasonable reality: