What determines left-handed and right-handedness?

What determines left-handed and right-handedness are the two alleles, or two manifestations of a gene at the same genetic location, that are associated with handedness. One of these alleles is a D gene (right) and the other allele is a C gene (chance). The D gene is more frequent in the population and is more likely to occur as part of the genetic heritage of an individual. It is the D gene that promotes right-hand preference in the majority of humans. The C gene is less likely to occur within the gene pool (can be influenced by external cultural and societal pressures), but when it is present, the hand preference of the individual with the C gene is determined randomly. Individuals with the C gene will have a 50 percent chance of being right-handed and a 50 percent chance of being left-handed.

Genetic combinations are DD individuals who are strongly right-handed, DC individuals who are also mostly right-handed, and CC individuals who are either right-handed or left-handed. These genetic combinations leave us with an overwhelming majority of human right-handers and a small, but persistently occurring, minority of left-handers.

I had no idea it was genetics!

I wrote a blog about it here. Hopefully this answers habibi's question

https://biology-forums.com/index.php?article=1546.0