I voted internal and external. external is related to fear of physical threat first and foremost, but I think it happens at other times. The internal shakes... little more complex to me. I am inclined to agree with kathy, as with most things - it is not the "event" or "action", but the impact and cause. Kathy also points out that intensity is an important factor.... most people experience a range of emotions and reactions to those. How extreme and frequent can say something quite different.

Kinda cool, this. I like hearing everyone's views.