Final answer:
The terms 'fight' and 'flight' are used to describe the sympathetic motor responses during stress. This response explains the increased jumpiness when watching a horror movie at night.
Step-by-step explanation:
The terms 'fight' and 'flight' are used to describe the sympathetic motor responses during stress. The fight response refers to the body preparing for physical activity to fight off a threat, while the flight response prepares the body to flee from danger. When you are home alone at night watching a horror movie, the sympathetic activity in your body increases, leading to an increased sense of jumpiness. This is because your body is preparing for either fighting or fleeing in response to the perceived threat from the movie.