Emotions arise only because of appraisal . However, it is important to recognize that not all appraisals arise from conscious thought. Many or most appraisals are unconscious. Since learning figures strongly in human behavior, appraisal often reflects specific socio-cultural norms. Each emotion represents a different biological adaptation.
Arousal is a common physiological response evoked by many different emotions.
Arousal entails increased heart-rate, respiration, glucous uptake, epinephrine release, etc. The purpose of arousal is to prepare the body for action. A reduced ability to sense one's body is correlated with a lessening of emotional intensity. Misattribution appears to be commonplace. Emotional states often result in characteristic changes in a person's physical appearance or in the sound of their voice.