Not sure about insights but I had three stutterers in my class when I was in school. In Ukraine where I'm from we have a huge amount of people who stutter. Firstly, it's because the Ukrainian and Russian language has more hard sounds. So English is a softer language and this is the reason why English-speaking people stutter less. I just realized that I know at least 30 people who have stuttering and who are in my friend circle. But I don't really like to be in one group with other stutterers in real life because I can't see how they want to be victims.