Well, scientific research frequently confirms already known theories. However, it is interesting to note the German researcher's bias that children are inherently selfish. I've known this to often not be the case at all; many children, even very young children, will protect a child they feel is being threatened. Oh, sure, they may whack each other over possession of a toy occasionally, but the sense of community seems to be there from very early on. I've known children in a classroom setting to help each other with the work regardless of whether there's a reward (such as extra recess) or threat of collective punishment (such as taking away recess). They even at times help children they normally don't get along with. These are informal observations and certainly don't amount to scientific research by any means, but it is interesting to see.
Note: Though I normally teach eighth grade and up, I have taught as young as kindergarten, so I have some experience in this area.