We (men) are afraid of rejection. The only way we know how to deal with our fear of rejection is to objectify what we are afraid of (woman) into something more managable.
The way a person turns something they are afraid of into something they can manage is by being thinking, "It is worth less than I am." or "It does not have feelings like I do.". There are other ways people objectify things they are afraid of, but I will stick to sexism for this post.
As soon as you say a person has less worth than you, you feel more powerful than them.
It's like this... You see somebody standing in front of you, and you get the impression they want to hurt you (whether or not they actually do want to hurt you is a different story...). You immediately engage in conflict with this person. And in order not to feel badly for hurting your opponent, you lessen their worth (in your own mind). This is when we can harm the other person and not feel so bad. Forms of harm include denying a person a job, failing then on a test, not giving them the right to vote, etc., etc., etc.
But what tends to happen when we engage in battle? People just start hitting each other, until both parties are bruised and bloody. Who wins doesn't matter so much, as the damage has already been done. This paragraph, by the way, is only a model for the results of conflict. Please take note of this before responding.
And who knows, maybe the whole thing could have been avoided in the first place.
If men didn't react to women with fear, perhaps they wouldn't react to fear with aggression.
What do you think?
P.S. I use the term "we" in a general sense. I personally do not think I'm sexist.