Human nature is a constant in history. From Hammurabi to Hubert Humphrey, from Babylon to Boston, people are people, and they do the things that people do: they love, they hate, they buy, they sell, they ask questions, and they answer questions. In a diverse array of constantly-changing settings, human nature is one of the fixed points.
Part of human nature is gender. Masculinity and femininity are also constants - societies have been compose of men and women since history began, and it will always be that way. But different societies construct different contexts around those two foundations.
At Yale, sociologist Stephen B. Clark concluded that "men have a natural tendency to avoid social responsibility."
Some civilizations have built social structures in such a way as to encourage men to take more responsibility.
Other civilizations have enabled men to be irresponsible (at the cost of placing greater burdens upon women).
This gives us an interpretive framework - a lens - through which we can view and understand various societies at various times. It also explains why, for example, we see trends in which the majority of responsible roles in a society are filled by one gender or another. In many high schools today, the class officers and student council reveal a clear trend: why are these roles filled largely by females? Why don't males seem to have much interest in assuming leadership roles in some circumstances? Perhaps because they've discovered that leadership is work, and they have not been trained to apply themselves to difficult tasks.
