A paraphrase from a new book I found, Primate Ethology (worst jacket ever) that the primary function of allogrooming [grooming of one primate by another] is to reduce or remove certain social "barriers" between individuals. The idea is that you start making contact, make someone feel good and safe, and you can eventually "pair off" with them. In some species allogrooming is only observed in conjunction with copulation which suggests that it's a courtship ritual. But, close physical contact is risky as an individual approached may not want to be touched and attack. Some species of monkeys have developed alternatives to allogrooming that can be performed at a distance, like tongue-pumping (*snicker*) and penile erection (*second snicker*).1
Approach-anxiety in Humans
Why the fuck did I quote that? Because dating and approach-anxiety is the same thing. When you approach a person at a bar, you're generally trying to groom them from close distance, except before touching (e.g., caressing) we groom, i.e., provide comfort and show that we're not a threat, with our words. 2 But just as with monkeys, there's a danger of physical assault, but in our world, what is that risk or fear? What are they worried about? Physical assault? Emotional assault? Being ostracized? Loss of ego, status, and reputation? Self-disappointment? Do we fear fear?
1 Internet-dating and this forum is a good example, at least for some people, of socializing and grooming at a distance. I thought that was cool.
2 As I was typing this, I couldn't help but smile at how absurd this whole thing is. Fine, I'll say it. I also think it's almost magical to be able to discuss it.