I have heard that stuttering may be hereditary. I have brothers and an uncle who have a nearly unnoticeable stutter. I am a moderate stutterer/clutterer. I was first diagnose with speech impediments in pre-school around the age of 2-3. I have a son, who at the age of 4 has shown no sign of speech impediment at all. To be honest, I am amazed by his articulation and how easily he produces sounds from talking to doing a beat box like routine while he is playing. So to sum it up, while stuttering may be hereditary, I don't think it's always the case.