CCN, my son will be 3 in October so I am not sure if socializing is that important to him at this age. He is very advanced for his age and spends most of his time at daycare looking at books, doing puzzles and spelling words he's learning. The other children are not into this and he appears to be a loaner. He is very social if you talk about things he is interested in, but kids his age are not where he is, so I think he is bored; I really don't know whether he is an introvert or extrovert.
He sounds just like my daughter at that age - she was the only one in her preschool who read and write & do math, and she was interested in different things than her peers. She also had intense anxiety and didn't want to be there - all she cared about were books, books, books.
I purposefully put her in a play based preschool so that she could learn to socialize and she spent a lot of time stressed and unhappy. The teachers told me there were times when she came out of her shell a bit and would play, so that was good at least. Both my kids (always have and still do) have a low threshold to the "sillies" and there was a boy at her preschool who was a class clown and made her laugh, so that was ok too.
What I had more success with for her (and my son) were play dates. I found them to be a better socializing opportunity, mainly because both my kids (myself as well) are better one-on-one than in groups. There's a
huge difference in the dynamic between group socialization and one-on-one.
My kids are now 8 and 9 and have a very fulfilling social life (I say no to play dates frequently now because I get exhausted, lol). Play dates are mostly done at our house which is my preference because my kids are so intense and reactive and I find that they still need my guidance sometimes. If it's just the two of them involved in a sibling dispute I tend to let them work it out themselves, but if it's a dispute with friends I discreetly intervene to ensure that their friends aren't alienated by my kids' intensities.
Anyway, it's hard when they're 3, because you don't have the future perspective to know they'll be ok even though they're different.
Does your son have play dates outside of class? Is there someone in the class he likes that he talks about? My advice would be to set up play dates outside of the class and not worry so much about what happens during. As long as he is connecting with other kids in a positive way it doesn't really matter where it happens.
