There is a genetic component and it can be passed down generations. My dad had a stutter (he outgrew it at 20), and I have a pretty severe one (neither of my two siblings do). For a long time I did not want to have children; how could I pass on the anguish and suffering I experienced and still do? My wife convinced me otherwise, and my daughter has no signs of disfluency. We can’t live our lives in fear. I’m glad my wife convinced me into the greatest blessing of my life.