I've read up a little bit on this actually and apparently on average stutterers IQ's are 14 points higher than the general populations IQ. https://psychcentral.com/lib/stuttering-myth-vs-fact/ http://weeklyworldnews.com/headlines/12772/stutterers-are-smarter/ https://www.quora.com/Is-there-any-relationship-between-stuttering-and-IQ