What are emotions?

Emotion is the complex psychophysiological experience of an individual's state of mind as interacting with biochemical and environmental influences. In humans, emotion fundamentally involves "physiological arousal, expressive behaviors, and conscious experience".
Emotion is associated with mood, temperament, personality and disposition, and motivation.
A related distinction is between the emotion and the results of the emotion, principally behaviors and emotional expressions. People often behave in certain ways as a direct result of their emotional state, such as crying, fighting or fleeing. If one can have the emotion without the corresponding behavior, then we may consider the behavior not to be essential to the emotion. Neuroscientific research suggests there is a "magic quarter second" during which it's possible to catch a thought before it becomes an emotional reaction. In that instant, one can catch a feeling before allowing it to take hold.
The James-Lange theory posits that emotional experience is largely due to the experience of bodily changes. The functionalist approach to emotions holds that emotions have evolved for a particular function, such as to keep the subject safe.

There are basic and complex categories, where some basic emotions can be modified in some way to form complex emotions. In one model, the complex emotions could arise from cultural conditioning or association combined with the basic emotions. Alternatively, analogous to the way primary colors combine, primary emotions could blend to form the full spectrum of human emotional experience. For example interpersonal anger and disgust could blend to form contempt.ensional "circumplex model" which describes the relations among emotions.
This model is similar to a color wheel. The vertical dimension represents intensity, and the circle represents degrees of similarity among the emotions. He posited eight primary emotion dimensions arranged as four pairs of opposites. Some have also argued for the existence of meta-emotions which are emotions about emotions.

Another important means of distinguishing emotions concerns their occurrence in time. Some emotions occur over a period of seconds (for example, surprise), whereas others can last years (for example, love). The latter could be regarded as a long term tendency to have an emotion regarding a certain object rather than an emotion proper (though this is disputed). A distinction is then made between emotion episodes and emotional dispositions. Dispositions are also comparable to character traits, where someone may be said to be generally disposed to experience certain emotions, though about different objects. For example an irritable person is generally disposed to feel irritation more easily or quickly than others do. Finally, some theorists place emotions within a more general category of 'affective states' where affective states can also include emotion-related phenomena such as pleasure and pain, motivational states (for example, hunger or curiosity), moods, dispositions and traits.
The neural correlates of hate have been investigated with an fMRI procedure. In this experiment, people had their brains scanned while viewing pictures of people they hated. The results showed increased activity in the medial frontal gyrus, right putamen, bilaterally in the premotor cortex, in the frontal pole, and bilaterally in the medial insula of the human brain. The researchers concluded that there is a distinct pattern of brain activity that occurs when people are experiencing hatred.