It is taught. Some men aren't competitive. Some women are. But in men is encouraged, in women is discouraged.

My mother is far more competitive than my father, for example. Yet, when she compete, she is called "aggressive" or accused of not being a "teamplayer". We are expected to be more pleasing. Even working on IT.

Competition taken to the extreme is bad. It leads to people to feel frustrated when they came second, even if second is a good position. And sometimes, what is required from you is that you help others. Yet, it is women the ones who are expected to offer support, not men.