Recently we have begun to understand more about the biological differences between men and women through the field of evolutionary theory. Evolutionary theory takes into account evolution and our physical nature. Gender differences are seen as ways in which we have developed in our adaptation to our environment.
For example, later in this book we will explore how the double standard in sexual behavior developed, in which a man with several partners was viewed as a “player,” whereas a woman with several partners was viewed as a “slut.” An evolutionary theorist would explain this gender difference in terms of the biological differences between men and women. A man can impregnate several women at any given time, but a woman, once pregnant, cannot become pregnant again until she gives birth. The time investment of these activities varies tremendously. If evolutionary success is determined by how many offspring we have, the men win hands down.