DS7 starts and stops and starts when he reads aloud for homeschooling. It seems to be a strand of perfectionism. He wants to read it just right, with perfect pausing and inflection, so he stutter reads several times before moving on. It's extremely hard to listen to and wastes a lot of our school time. I'm working on it with him...

Long story short: I suspect a strain of perfectionism with this sort of behavior, whether in speaking or reading.

Kriston