*So why do I stutter at-all? Surely it cannot be genetic if my father and mother do not stutter? How far back do genes/genetics even go?* You should familiarize yourself with Mendelian genetics and the concept of dominant vs. recessive trait inheritance. It is entirely possible for a recessive genetic trait to be passed on for multiple generations without it being phenotypically observed. The more generations that go by, however, the lower the chance of that trait ever being expressed. Also, you mention one grandma and one grandpa. Alive, dead, known, or completely unknown, almost every person (hopefully) has four grandparents. Finally, you say nobody that you know of in your family stutters. My SLP says she sees adult clients who have been married for years or decades who are very internalized with their stuttering. Their spouses and families have no idea they struggle with their speech in any way. While the odds are against it, for all you know, one or both of your parents (or grandparents) deal with their own stutters.