Sometimes my kid likes or is not bothered to exchange toys and play fine with other kids, either younger or older.
Other times, he likes to have what he wants and screams and cries if some other kid is chasing him for the toys he's holding. Or he cries for toys others hold and are not his but he wants them badly!
He prefers older kids and enjoyes when one of them likes to play with him - though at times this transforms into an amusement for the older one... Or at least some of them try it but our son gets bored or gets the idea if the other child doesn't know how to play...
I don't remember where exactly, either in a book or article, I've recently found that kids, till they reach a certain age (6 ? ) usually they don't play
with each other, but they play independently though they stay together with other children - it's normal they say. They become more social oriented after they reach the "school age".
Our son sometimes surprises by acts of love - he likes to embrace children as he always likes to embrace us. For him this gesture means he likes that person, likes to be around and play with him or her (same attitude with animals).
Oh, he's never showing himself off. Especially when we're outside the house or outside our family. But sometimes he names things or beings in another language or likes to sing a song. Still that comes naturally and rarely. Usually, in society, he's acting like a normal, sociable Romanian child of his age