Rumor: Will Left-handed People Be Smarter?
Truth: If [intelligence] refers to IQ, then left-handed and right-handed IQ are similar.
If we only look at certain fields and abilities, such as science, music, politics and other fields, there are indeed famous left-handedness, but these examples cannot be used as better evidence for left-handedness.
We can always list more outstanding right-handed people. In the whole population, intellectual performance has nothing to do with left/right-handed preferences.
There is no authoritative research to give a clear conclusion as to why left-handed people appear and why they are always in the minority. We cannot say that left-handed people are smarter just because many celebrities are left-handed.