When most people kiss they tilt their head to the right. OK, I get that … 90% of people are right-handed so tilting right feels natural.
But I’ve noticed when people hug, they almost always lean to the left (putting their head over the other person’s right shoulder.)
Why not lean right when hugging?
They do? I’ve never been much of a hugger but I go right when I have to do it.
Went right, got left behind!
Think about it. 
People tell me that, regardless of whether someone else is zooming in for a kiss or zooming in for a hug, my head tends to snap back so as to keep as much distance between me and that other person as possible.
Oh, Lord, someone is going to try and touch me!!!