Left-handed folks aren't as rare as people with polydactyly or syndactyly (webbed hands or feet), but you may have noticed that there aren't as many left-handed people out there as right-handed people. Some of this is due to societal pressures, but I was intrigued to learn that much of it may have to do with genetics, and these genetic mechanisms may extend not just to which hand is dominant, but how the body plan is determined. Like many things in bioscience, it isn't always apparent that handedness and its genetic components are critical to other aspects of physiology, but as we will find out together, the genes associated with whether you use one hand more efficiently than the other can also influence developmental and neurological health!