If your sources are pretty high school why should anyone here listen to them?
Maybe not everything is an exercise in pushing an economic ideology.
If your reasoning here is, that every person just does what feels good for them and therefore everyone is just "selfish", then that certainly isn't the whole picture why people do what they do.
There're certainly people doing things because they feel right, but it might not be a pleasure for them doing it.
Reducing everything to just being selfish doesn't make that much sense.
Person wishing to do the right thing and doing it ("unselfish")
Person doing the right thing against their wishes ("righteous")
Person wishing to do the right thing but not doing it (akrasia, you missed this one)
Person not doing the right thing and not wishing so ("selfish")
It's all about image of oneself and the experience of being burned by your actions, and every person out there shows plenty of behavior from all four quarters. So dividing people doesn't makes sense. Now, dividing actions does.
It seems it's more about you thinking that someone else does this here or in the study.
> Now, dividing actions does.
But the study is about actions and how people feel afterwards. It isn't about unselfish people, but about unselfish actions of people.
Sure, if they call the group 'unselfish people' it's not quite right, but that's not the point of the study.
It doesn't make terribly much sense to imagine that people can be divided into two groups, "selfish" and "unselfish".