Thanks for the inspiration, but I think some things need to be corrected. Not all stutterers are completely fluent when alone. Surveys show something like 2/3 of stutterers never stutter when alone (or speaking to pets or babies), and the remainder stutter less and a few (like around 5%) stutter about the same. Something about the process of communication triggers stuttering. When we are alone or talking to an animal or a baby (beings who do not even comprehend too much of what we are doing), we are not really communicating - we are just making sounds to ourselves. And for some people, maybe this is communication too, so they stutter. I won't claim to understand what is happening during a stutter, since scientists don't really have the neurological part nailed down at all, but I think you are oversimplifying it. The speech process is a complex one, when you think about it, with all the mental and physical things involved. But I am pretty sure it is not just stress. Everyone gets stressed when speaking sometimes (like with a public presentation), but most people do not exhibit stuttering, just nervousness. So I think it is important not to get cause and effect mixed up.