Yes it’s weird but each of us has different causes of stuttering too. Usually we stutter more in unfamiliar venues than around accepting family and friends, maybe because we are under less duress because they already know we stutter and love and accept us anyway. Strangers and new work associations do not. Our anxiety is higher. That’s why when giving a presentation we often modify the audience’s expectations by disclosing at the beginning that we may stutter. These things tend to lessen our anxiety about speaking. It might or might not be appropriate in other situations but disclosure helps. About stuttering less around familiar people, that’s very common. Sue