How might we prepare students for a life of mass-sharing?

This is a question that occasionally pops into my mind every now and then or should I say each time my students demonstrate that sharing is not something they are particularly good at. At young age kids are more likely to gravitate towards clear cuts between mine and yours, starting with “my pencil”, “my eraser” to “my idea - stop copying”. This is why sharing is not an easy skill for them. In order to help them realize the benefits of cooperation we started reading stories that have a clear massage of what people can achieve when they are willing to work together. However, what kids of young age are good at is doing things without realizing they are doing them or in this case sharing without knowing that they are sharing. This happens each time we brainstorm things we know about a certain concept, figuring out how to solve a given problem, sharing ideas about text read etc. Also group activities are an excellent way of proving how they can put their minds together. What I try to do is arrange the groups so that the students whose opinions differ a lot are put in the same groups. This way I know that there will come a certain point when the clash of opinions will happen. That’s when I as a teacher step up as some sort of facilitator and help them incorporate what both sides are saying into their work. Often they end up being surprised that they can gain something out of a disagreement. I think the best way to prepare them for a life of mass-sharing is just to constantly show them trough work and practical examples how sharing enriches their learning and helps them come up with ideas that they would not be able to think of without a little nudge from others.