I think it’s partially true. I think we don’t give our mind enough credit to help control our stutter. I use to stutter on words in my childhood that I don’t now as an adult. I also realized if I’m able to hold a calm state of mind and take my time speaking my stuttering is either eliminated or greatly reduced. Though that is truly a challenge since naturally I have a lot of anxiety with the most basic things. There’s also the fact that I stutter a lot less when I’m drunk but again I think my state of mind plays a huge a roll in that. Anxiety is very minimal and I tend to be “braver” or have more confidence in speaking when I’ve been drinking.