I think I'm the odd man out here, because I'm a habitual hugger. I think that might have developed from my teen years doing musical theater, where all everybody did was hug each other- man-man, man-woman, woman-woman, person-tree, etc. - and so I was forced to very quickly become comfortable with the idea of human contact, not to mention the fact that in a number of shows, I would have to kiss people on-stage (I never kissed anyone romantically until I was 18, because I was uncomfortable with that level of intimacy up until then).
That said, I have had to learn that giving or receiving a hug is very situational, and that my first and foremost priority has to be paying attention to my own gut feeling of safety/security as well as the verbal and non-verbal cues the other person is showing. A mutual sense of security has to come first. This is complicated, because a verbal agreement around something like that is rarely made, especially if the person is a stranger or an acquaintance.
I have been in situations where someone will say to me, "I'm a hugger," which usually is their indirect way of communicating one of two messages:
1) "Just a heads-up that I hug pretty liberally so I'm probably going to want to hug you when we're done."
2) "I'm pretty secure with my boundaries, so if the vibe between us is good and you want to come in for a hug, I'll welcome it."
(Or then there's the third option, which is when I'm on a date and they say "I'm a hugger to me", which usually means, "I enjoyed myself, it looks like you did too, I'm not ready to kiss you, but let's make some physical contact and see if any physical is there.")
I have been in situations where I will flat out refuse to hug someone, and that's usually when I feel like I'm being somehow played or bullshitted by the other person, or that they violated my personal boundaries somehow. But usually, there is enough physical distance between us anyway that we could both go our separate ways and not think anything of the fact that we didn't hug.
I have also been in a few situations in which someone spontaneously hugs me - or I spontaneously hug them - after we have discussed an experience that was traumatic or intensely personal for them. The fact of the matter is, in moments like that, as gratifying as a hug like that can be, in another way it's intensely impersonal. They (or I) don't want a hug from that other person, specifically; we want to hug the person who listened non-judgmentally and was present to work through that particular moment. A hug like that is usually out of gratitude mixed with a need for some physical reassurance, as though the emotional truth of what just happened cannot be fully internalized until that hug happens.