I grew up, at least into my teenage years, not hugging much. Our family didn't really do that. I am getting better at doing it with guys and girls, like when we are parting ways. I still am uncomfortable hugging girls I don't know well. With girls that I know, like friends' girlfriends, I sometimes hug but it is a little awkward if I've set the precedent that I haven't been hugging them.
And it seems to be more awkward being 6'3" and trying to hug a girl that's 5'3"...it just doesn't flow naturally. I have to lean down far or else wrap my arms around her head and shoulder and her head is on my chest. It just seems easier for guys that are average or even a little short to approach women for a hug since they are less intimidating.