It Totally Depends On the Person and the Circumstance
I am not the person who goes around and hugs everyone just for the sake of it. I think that hugging someone is something personal and to me it has meaning. I hug close friends and family. If it is a good-bye hug it is often a one-arm hug and short. If the other person is going through a rough time I do the 2 arm hug and hold them tight and for longer and I have also done the back rub with it to ease their tension and to make them feel good.