School Responsibilities

then hard disagree about your hard disagree about my hard disagree - most any psych/sociological experiment will show we're fundamentally social/cooperative. in fact it's hard to imagine our species surviving if we were fundamentally self-interested (basic biology couldn't give 2 farts about the individual, it's built on diversifying the gene pool to ensure adaptability and thus survival) - and supposedly we can live in a fairly egalitarian tribe of up to about 75 or so people (maybe even 200+)
it seems like our big social shift was cultivating grain which allowed us to harvest then store it - at that point, the tribe not only needs 'soldiers' to help defend from outside forces, but also 'police' to protect assets from inside

Those same experiments also show that we have a endorphins and other hormones release when we are cooperative. Which suggests that the motive is really self-interest and feeling good because we conformed. Also, those experiments don't take into account the amount of socialization that we have toward forming social/cooperative groups. It's why psychology isn't a hard science. They can't control the variables in experiments without doing some very unethical things.

Beyond that, all of the above ignores why we joined into those social/cooperative groups in the first place which was for self-preservation/self-interest. The fact is that even when we are in groups we tend to attack other groups because we are not hard wired to group together, we are only hard wired to group together for protection. Which is why we will as a group attack those that we see as different or a threat to our group. We do it with minorities and others not in our "tribe" all the time. The fact that we need "Police" and "soldiers" is proof positive that we don't have natural instincts to be kind or help others. It's not at all surprising that after living our lives in a more or less cooperative society we always see it as a good thing and in our self-interest. It's because it is a good think and in our self-interest which is why we tend to enter into them.

And, the reason we tend to have more success living in group/communal settings in small numbers is because those groups tend to be made up of like minded people committed to that specific goal because it makes them happy. You can't just take 75 random people and do that. If you do, you end up with Lord of the Flies. Again the problem with those "experiments" are that there are no controls so no valid conclusions can be drawn.

But, frankly, there is probably no provable right or wrong answer to this. As with all things in the realm of psychology, the best we can do is make guesses since you can't do the controlled experiments necessary to confirm any hypothesis.