system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: Why is right-handedness dominant?
gpt
One theory:

The reason we have hand dominance is for practically using tools effectively. Humans cooperate using tools all the time. A right handed tool will not necessarily work for a left handed person. In this case, humans evolved to create a hand dominance through cooperation. Those early civilizations that had a hand dominance were able to cooperate more, which led to better successes. Why it was the right hand could be just considered coincidence.

So why do we have left handed dominance? That's because just as important as it was to cooperate, it was also just as important to compete. If you look at professional athletes today, almost %50 of them are left handed, which is an extremely higher percentage than total number of left handed people (less than 10%). Civilizations that had at least *some* left hand dominant people were able to compete better.

TL;DR - Majority dominance allows more cooperation. Minority dominance allows better competition.