There is some evidence of genetics playing a role, but almost as much evidence as genetics NOT playing a role. There have been studies on families with stutterers, families with just one stutterer and on twins where one stutterers and the other doesn't. For example: No one in my family stutterers and I'm an even rarer adult female stutterer. If you do have a child, please consider speech therapy if a stutter starts to show up.. but also understand that many, many children stutter as a part of speech development and they outgrow it. Only 1% of the adult US population stutters. The chances are low, but they are there.