Yes this is pretty common I'd say. Its rooted in how we essentially view ourselves/self worrb etc etc. There may have been a point in our developmental stages where we most likely been made to unintentionally made to feel self conscious and to doubt ourselves in some way Sensitive children seem to be most vulnerable to this, and it can take the slightest mishap to steer that communication ship off its course.. So factual taking is key to the brains stress response becoming overwhelmed and displayed speech impairment. De sensitising therapy is one of the key ways yo overcome this.. but it takes a lot of commitment.