Oof, there is a lot of controversy around speech and stuttering and whether or not "behavior" is an accurate term. In some disciplines, "behavior" implies voluntary choice. For the most part, the act of speaking (speech production) is voluntary. It's a behavior, or more accurately a combination of behaviors. Stuttering, on the other hand, is usually involuntary. Secondary behaviors are absolutely behaviors (hence the name), These can be volitionally controlled, although it may take time to eliminate habits. But the core stuttering manifestations of blocks, repetitions, prolongations are usually not within the speaker's control. They aren't *choosing* to "behave" that way. So what do you call it? (For the record, there is no consensus here... One of my colleagues, arguably the most well-known expert in this area, has said he wants to host a retreat with a bunch of people where the goal is to figure this question out!)