If you '' don't really know why stuttering happens '', what makes you so positive that it is not psychological? I suggest you go on Youtube and look up the Secret of Stuttering by Dr. Mort Cooper PHD. That'll give you some more insight into stuttering and why it might be happening. Stuttering is not a simple thing, there are many tiny details that are working in the background. Psychological details. As a stutterer myself, I can tell you that there have been times in my life where my stuttering has gone, and then come back again. Do you stutter when you are by yourself in your room and no one else is around to hear you?