Okaaaaaay we gon' do dis: The cause of stuttering is unknown. There is a school of thought that it is genetic, as 30-65% of people with a stutter ALSO have a family member with a stutter. But is stuttering genetic? Maybe, maybe not. There's still that percentage of individuals with a stutter with NO family history of stuttering. What about psychological/ emotional? Children who have witnessed the tragedies of war have developed stutters (called psychogenic stuttering). What about something in the brain? Adults who have head injuries have produced a stutter after their trauma (called neurogenic stuttering). What about children who stutter and their parents never did? Stuttering can be psychological (thought, feelings, emotions), environmental reactions (they stuttered, got a bad reaction, then developed anxiety about speech), physiological (yo brain is different), genetic (family history of stuttering), an error in the motor speech planning and feedback loop (you go to say something, goof, hear your goof, then get stuck), or neurological (you hit yo damn head). It is a mix, combo, clusterfuck of all these things. Whatever the CAUSE of stuttering, the EFFECT it has on your communication can produce fear and anxiety for the reactions of your listeners. And if your anxiety is up, your stutter will likely worsen, causing more anxiety, and the loop replays. No matter the source of stuttering, there is likely a significant emotional element at some point in the individual's attitudes about speaking. It is never purely emotional, physical, genetic, whatever. Hella complex.