i think it often can be hereditary and tends to run in families. i think you'll find more people than not on this subreddit will have relatives who stutter (just my observations from reading comments on this thread and others). i have a stutter just like my father despite him being completely absent in my life so i don't think it's environmental either. apparently half of children who stutter have another pws in their family. ((source))[https://www.stutteringhelp.org/risk-factors#:~:text=Family%20history,family%20member%20is%20still%20stuttering.]