I dont know for sure, but as a young child (c. 18-24 months old) there was a lot of stress at home (Mum had to have major surgery) and I had to live with a grandparent for 6 months. Too young to have memory of that time but I've often thought its logical that the stress as I was learning to speak might've impacted my development, or perhaps I just was born with the stutter (no known stutterer's in my family though).