I understand the dismay of seeing starkly different behavior divided along gender lines, even if it was unintended, especially when it involves personal space. I also understand that socialization and our gender biases play a huge role in our behavior.
Btw, we all have gender biases. If you think you don't, you are either an extraordinarily rare specimen or you are blind to your own (odds are very high on the later). It's ok. It's very difficult to be aware of automatic behavior and thinking. But be aware that there may be an aspect to who you are of which you are not cognizant.
As for hugging vs handshakes, I'll leave it to this which I think nails it pretty well:
http://www.mannersmentor.com/social-...reat-greetings