The _____ of an emotion is the degree to which the emotion is reflected in an individual's being active, engaged, or excited versus passive, disengaged, or calm.
The answer is arousal level of an emotion. The arousal level of an emotion is really depended on the individuals' view and cognition toward a certain situation, which means that the arousal level of an emotion that displayed under the same situation may vary from one individual to another. For example, one individual may got really excited when meeting a certain celebrity while another individual might not feel anything.