This is because emotions are evolutionarily old. Įmotions vary widely in how they are implemented in the brain. Įvolutionary psychology might define emotions this way: 'Emotions are a type of program, instantiated in our neural circuitry, that coordinates elements of our psychology and physiology in response to a recurring ancestral situation in a manner that tended to increase the chances of survival and reproduction.' Įmotions are distinguished from 'moods' in that moods are longer lasting and tend to build up over time. Other things we associate with emotions are vocal expressions, physiological changes (such as an increased heart rate), subjective feelings of emotion, readiness for particular actions, and psychosocial functions. The disgust expression crinkles up the face, reducing the chance of a pathogen entering the body through the eyes or nose. For example, the fear facial expression expands the nasal cavity and widens the eyes, enhancing smell and enlarging the field of view.

Even the facial expressions of some emotions can be related to their evolutionary function. Fear, for example, prepares you for fleeing or fighting by raising blood pressure, increasing focus, etc. Emotions also tend to have 'action tendencies.' That is, emotions are not just feelings, but they tend to ready the body for certain kinds of actions. From an evolutionary perspective, emotions are like the automatic settings on a camera, in that they tend to produce behavior that is generally adaptive, without requiring deliberative thought. At best, you can choose to do something that you expect will make you angry.

Emotions kind of feel like they happen to you, and might choose to deal with them. That means that you don't choose to be emotional or not, for the most part. It's difficult to define what emotions are, but in general they share some characteristics.

Intricate Emotions by J. Ramirez