Grading Hampers Cooperative Information Sharing in Group Problem Solving

I've read a lot about it being called a zero-sum game, right? This idea that we cannot both win. It's just not possible. I'm like, who said? There are all kinds of games and activities you play where you think someone has to lose, and then you realize, did you have to? The sharing of the orange. You all have seen these activities, but wow. I don't want to talk about where it came from, but I am curious. It's so ingrained in this country, and probably other countries, but I don't know.