The more I read, listen and think about it, the more I realize what an important part does the intelligence plays. People with higher intelligence can coast in school and not do any of the work at home, which gives them time for doing other stuff in the afternoon. On the other hand, people with lower intelligence have to also work at home to be able to keep up. This gives the intelligent people a leg up, so they can use this additional time for anything else, from meeting people and playing, giving them an edge at social skills, to studying additional material, which gives them a bigger breath or depth then others or just for relaxing, creating better memories.
Even at the jobs, the intelligent people tend to learn quicker and they require a lot less hard work to be able to master and optimize given work, so they do it with less time and energy. Less intelligent people can play catch up with hard-work and that can compensate for it at least in part. But having two people with the same work ethics, the one with higher intelligence will win.
I think this is nicely shown in the Price law. The price law says that the squared number of people produce half of all the work.
sqrt(n) = 1/2 * work
It was originally created looking at the productivity of the scientists, but I think it works just as well here. This means, that if there are 100 people working, then the top 10 produce half of the work, and the rest of the 90 produce the other half of the work. I guess in a way, it can be linked to the Pareto law.
Though I did hear a different explanation of the law. It is that the competence increases linearly, but the incompetence increases exceptionally.
That this is means, that I imply that less intelligent people should stop working? Not at all. Unlike in the investment field (where the same principle apply), I do believe that everybody that is willing to work hard can make a contribution to a better working of a community or society, whichever one you prefer. It is just, that their contribution is most likely going to be lower than equality hard-working person that is also intelligent. And we currently live in the society, that this matter in what kind of rewards the society gives back to the worker for their work.