I'm a "natch" lefty. Interesting that US stated stats are ~16 -20 % left. In whole world, it is supposed to be slightly lower. Plenty of places still actively practice latent 'conversion' of young people (students) from L to R - for same stupid endemic reason educators and others used to do in USA.
My opinion only, I bet that it is much more likely the 'true' left dominant population WW is probably 33%. Lotta folks converted at early age. In my case, I write with a 'crook' hooking my left hand becuase I was never shown how to position my writing tablet back when practicing going from Block to Cursive in like kindergaden or 1st g. Too hard to break later. L prob much more ambidextrous than R handers.
From my limited personal stats observation, Lefties seem to be way over-represented in the Sciences.
ST