I have seen a lot of manosphereans saying that women are collectivist and men are individualist. Of course they also imply that this is biological.

This is by far one of the most ahistorical things manosphereans say and frankly it only serves to push a certain political narrative. (right-wing politics are "masculine", left-wing politics are "feminine. Of course the fact that right-wingers also promote certain types of collectivism is largely ignored)

Masculinity is just as collectivist as femininity. Just look at one obvious example: the military. The military is almost exclusively masculine and its structure is obviously collectivist.

The truth is that "individualism" in the way these people mean it is a very recent idea and also largely unknown outside of western culture. How can individualism be an inherent part of masculine nature when it can basically only be found in a certain group of people?