Emotions are probably the most fascinating of all mental processes and involve two phases of feeling and reaction. Are these two phases necessarily interwoven? Of course, they are. There could be overt or covert reactions to emotions but there is "always' a reaction and an associated feeling. Much has been written in psychology about emotions and there are now many theories and according to the most influential James Lange theory, emotion is a perception of bodily states. This means there is first a reaction in the body and when there is perception of this reaction, emotions are experienced. The body reacts and creates a feedback and only then we perceive the emotions according to this theory. This theory would suggest that emotion is a bodily reaction followed by the perception of such reactions.
There are many studies on the physiological or neurological aspects of emotion and most of these studies have suggested that the limbic system comprising of the hypothalamus, the hippocampus and other structures are responsible for expression and perception of emotions. There are many categorizations of emotions and one of these highlight emotions caused by internal body states such as pain or hunger and emotions caused by external stimuli as in the case of anger or fear. Emotions could be positive and negative as we know as the positive emotions are love and happiness, empathy, affection, curiosity, ecstasy and the negative emotions are jealousy, hatred, grief, anxiety, frustration etc.
The categorization of emotion could be
1. Internalized (based on internal stimuli) or Externalized (based on external stimuli)
2. Cognitive (based on cognitive activity such as judgment), Affective (based on explanations of feelings or emotional experiences) and Somatic (based on bodily experiences).
If emotions are based on a psychological aspect of feeling and a physical or physiological aspect of bodily reaction, it is usually a question of which comes first, the feeling or the reaction? I would suggest that emotions based on internal stimuli could first involve a feeling or a psychological condition and this would in turn cause a bodily reaction. Depression for instance could cause sleeplessness and other physical reactions. Emotions based on external stimuli as in anger could first involve a bodily reaction as when there is a heated argument we feel a faster heart beat and other bodily reactions. These bodily changes then produce the psychological aspect of anger. Thus in internalized emotions reactions are triggered by feelings and in externalized emotions, feelings are triggered by reactions. There could be further research in psychology to clearly demarcate internalized and eternalized emotions. Feeling is thus a psychological component of emotion and the bodily reaction is a physical component of reaction. Emotions are thus more complex than feelings and have two distinct components. For example emotions such as romantic love would consist of a feeling component of overwhelming affection and a bodily need or reaction related to physical desire. Simple affections as consideration for a family member is more of a feeling and do not involve bodily reactions. It is necessary in psychology to clearly distinguish between feelings and emotions and more research will be required to identify simple feelings from complex emotions. An emotion is always necessarily accompanied by significant bodily reactions.
The distinction between feelings and bodily reactions in comprising emotions could help us identify these two essential components for each emotion. For example anger is a complex emotion comprising of a feeling of irritability and a bodily reaction of rapid heartbeats, reddened face, etc. An emotion of anxiety has a fear component and a bodily reaction of sweat or trembling etc. Psychological studies have usually overlooked the feeling component in emotions and also emphasized on bodily reactions rather than identifying feeling as a separate and essential aspect of emotion. Recent studies in consciousness have tried to understand what feeling really is and it is essential to identify the emotions and also the associated feeling and reaction components.
I'll provide a short table here providing the feeling and bodily reaction components of emotions.
Anxiety - Fear (feeling component), rapid heartbeats (bodily reaction)
Love Affection (feeling component), physical/sexual need (bodily reaction)
Anger Irritability (feeling component), flushed face or deep breaths (bodily reaction)
Grief Sorrow (feeling component), tears or other physical changes (bodily reaction)
Lust Possessing (feeling component), physical/sexual need (bodily reaction)
Jealousy Controlling (feeling component), physical needs/violence etc. (bodily reaction)