My son is 15 months old and an only child. (we're due in June with our second) I have a babysitter who watches him and another 18 month old. Whenever new toddlers or babies come over to play/visit he will absolutely do everything he can to take everything away. I've tried having him pick out a toy for his friend and one for himself, and when it comes time to giving it to the baby, he pulls it away. I've tried "NO" and removing him from the situation...he walks right back over. I've tried saying "We must share. After he's playing it's your turn"..nada. HELP??! Or do I just let this ride itself out??
Re: Is sharing toys teach-able???
This is what we do. "J, can you give mommy the brush? Thank you!" "J, would you like to hold the brush? Yay!"
burp
We do my turn/your turn a lot. My youngest already gets it and waits her turn or moves onto something else. It might be more temperament--my kids are just patient and easygoing.
Also, if my oldest wanted a toy my younger child had I would have him get DD another toy to play with. This doesn't work as well now that she's older but it's something that's helpful for when your #2 is still an infant.
Are you trying to teach sharing or taking turns? They're different.
If it's a single item that they cannot both play with, they're not sharing, they're not both using it. They're taking turns. And you can just enforce taking turns - you get it for a minute, now it's the other person's turn. (No "can you give it to...?" nonsense. "Please give it to...", as it's not a choice.) And YOU can take turns with him too - take turns playing with his toys, ask him to take turns playing with your "toys", and talk to him about you and other adults taking turns, including pointing it out when you see others do it. And praise any little bit he does.
Same type of thing about sharing - if it's something they CAN both simultaneously play with or it's something that is divided and you get less of (like sharing food), call it that. Know, though, that this sort of thing, real sharing, is harder for toddlers - they don't get what they wanted to have, even for short periods of time. They get less. But instruct, practice, talk about it, praise it.
It can take a long time to learn, and you have to be super consistent in your teaching of it. But it can be taught.
And you might consider letting him "put away" a couple of special toys that he doesn't want anyone else to play with. Everything else is fair game to share and take turns with, but a few special things he doesn't have to share or take turns with (though maybe he can't play with them while other people are over... depends on the toy... I wouldn't have the "you can't play with it either" rule for a lovey, for instance).
DS: 11/8/11 | 9 lb 7 oz, 22 in
DD: 5/22/14 | 9 lb 9 oz, 21.5 in
This is exactly what we do as well.
I do think it's teachable, but at a certain age.