If you dont' want to read THIS ARTICLE, that's okay, I'll tell you what it says. Basically, the mom writes that she doesn't expect her son to share in all situations. She claims that ownership is a valid point in all human interactions and that in the real world, we don't all have to share.
I know, at first I thought, "Not Share! What? Everyone child everywhere has been taught how to share."
But, I totally get her point and have to agree that sharing is not necessary in some circumstances. Certain toys are communal, like playgrounds. It's polite to swing awhile, then give someone else a turn. It's also okay to find something else to do if the swings are occupied. Should you share a drink? Nope. If you bring a jumprope do all the kids need a turn at it? Nope.
But, if a little person visits our house then my kids are expected to share. They aren't brats and they need some manners. Sharing is good manners within your own home.
In the case of siblings, my boys are expected to share to a point. If a brother wears your shirt or plays with your Spiderman that was laying on the floor, then that's fair game.
But, I have noticed as they get older that ownership cannot be overlooked. It's okay to have your own things. To stake claim to something and call it your own. To tell someone to get their grubby hands off your stuff. I do it myself. And, I'm okay with the boys drawing a territorial line across the entrance to their rooms. I actually encourage it and consider it a sign of respect and privacy, something everyone should be entitled to in their home.
But, the author stretched it just a bit when she said that sharing caused a sense of entitlement to kids. Hmmmm .... I don't know about that. I'd say the new generation's sense of entitlement comes more from what their parents have given them (everything) rather than what they're taking or giving other children on the playground.