Re: Do parents teach selfishness ?
Depends on the parents. Children essentially emulate the behavior of the adults around them, and if they see their parents being stingy with their possession, or discussing things in terms of "mine", children will typically grow up to follow the same pattern. If they see their parents spending on charity, volunteering, and sharing with others, then they will likely do the same.
Children need to be taught from an early age the value of giving charity, volunteering, and sharing toys with other children while playing, but they also need to be taught personal responsibility (this is your toy, take care of it, and put it away when you are finished with it, don't give it to anyone without a good reason). I have no problem with my kids putting something in particular up on a shelf when certain kids come to play, because we have learned from experience that they are destructive and break certain things. Islam does place a high value on individual ownership, and respecting others property.
We also stress the importance of personal space to our kids, not invading others privacy, and respectfully not allowing others to invade theirs. Children need to be taught balance and moderation in everything.