That’s what happened to me in my late teens. I was dealing with a lot of stress (from a heartbreak, expectations from family, perfectionism, school) but I felt like I had to suppress all of it in front of my friends. Then one morning a friend came up to me asking how I was doing and I stuttered for the first time and everyone laughed. And then all of a sudden I had a paralyzing fear of this weird speech block that just happened. To me it was like my body couldn’t fake it anymore. I wanted to project positivity and suppress all the sadness but my body couldn’t contort itself anymore so it blocked. That’s why I think stuttering can be akin to any other block like not being able to pee in a urinal with other people present: your mind wants to pee but your body doesn’t. Same with stuttering. Your mind wants to speak but your body doesn’t Edit: I wouldn’t say my emotional state caused my stutter but it helped trigger it. The cause is probably a huge range of factors, some of which we still don’t understand and others that we do like genetics.