Serious Sam

Why a person turns out to be right-handed or left-handed is not a mystery.

Handedness is partly heritable . Left-handed parents tend to have more left-handed children than right-handed parents do.. Note, however, that if handedness is only 25% heritable, then the majority of the factors contributing to left-handedness is not straightforwardly genetic. A much debated influence is the level of the hormone testosterone in utero (in the womb) while an unborn child (fetus) is developing. Another possibility is that handedness is influenced by random (“chance”) processes that occur during the early development of an unborn child, when it is still very small. Regarding the heritable factors, researchers have found several genes which may be involved in handedness. Interestingly, it seems that there is not one gene which contributes to determining whether people are left-handed or not. Most likely, different genetic influences are involved.

Left-handers are a sizeable minority of people (at least 10%). Hand preference is partly heritable, pointing to a genetic contribution. However, the relevant genes are likely to interact with environmental and chance factors to determine the handedness of a specific person. The brains of left-handers and right-handers are somewhat different. Left-handers tend to have less lateralized brains, meaning that the two halves of the brain are less distinct than in right-handers. The study of left-handers can help us answer several important scientific questions. All of this means that left-handers have many reasons to feel special, for after all, the large majority of people are not left-handed. At the same time, bold claims about creativity and other ways in which left-handers may be super-gifted are probably not true.

More on this.

Here is a clip I want you to see

I will be sending you more questions soon