Eli5:what’s the cause of someone being right or left handed? And why the vast majority is right handed?

Question

Eli5:what’s the cause of someone being right or left handed? And why the vast majority is right handed?

In: Biology

Answer 1

I am a lefty that does some right handed things like throw (taught to throw) but not kick ( more innate it seems). i bat right and play golf (taught but also no way we could afford two sets of golf clubs so dad and I shared and he had right-handed clubs.)

My hand0writing is not good but I can print pretty good right handed, neater but slower. I can also print upside down pretty, pretty, pretty good, and I though everyone could do that but it seems to not be the case as when I did this in front of people on a white board everyone was like, “WTF?”.

So how many lefties can write upside down with ease?