Mood-congruent memory is the tendency to recall experiences that are consistent with one's good or bad mood. Thus, if the subject is upset, he is more likely to recall negative memories during which he experienced a similar emotional state.

Paul Ekman was primarily responsible for identifying many of the possible emotions of the human species and how these emotions were expressed facially. He argued that emotions were universal, though culture produced varying factors on to what extent they could be expressed and what situations/ideas would evoke which emotions. He came to this conclusion by studying emotions across cultures.

Type A personalities are characterized by high competition, a sense of time urgency, and negative feelings including anger, stress, and hostility. Type B personalities are characterized by low competition and an overall easy-going attitude. People with type A personalities tend to become easily stressed and have more difficulty coping with stress than type B personalities. Studies on the differences between type A and B personalities have revealed that type A personalities are also at higher risk of stress-related diseases.

Capgras syndrome is when someone believes that a family member, friend, or pet is an imposter and can't be convinced otherwise. Capgras syndrome often occurs after a coma or head injury.

Difficulty reading facial expressions and repetitive, stereotyped movements are associated with autism, flashbacks with PTSD, and compulsive order with OCD.

“Affect” refers to the experience of having an emotion. The “degree to which an experience is positive or negative” and “the experience of sympathetic autonomic nervous system responses” are the definitions of valence and arousal, respectively. These are both components of emotion, but do not encompass the entirety of affect. Last, the “strength of a stimulus’ effect on attention” is the definition of salience.

Type A personalities are characterized as being very competitive, goal-driven, and impatient. Additionally, Type A personalities are most likely to exhibit high levels of anger, hostility, and cynicism. While all humans will, at some point, experience lethargy, sadness, happiness, and depression these are, specifically, not characteristic of a Type A personality.

Catharsis, when being used in the context of psychoanalysis, most often refers to a release of pent up, repressed, or strong emotions. These are often negative in nature, such as sadness or anger. In Western societies, it is most often aggression, due to the fact that aggression is a socially unacceptable emotion to display in public.

There are seven "basic" emotions that have been observed in nearly every culture on earth, and are recognizable between cultures even if those cultures have never interacted previously. These fundamental emotions are: joy, sadness, anger, fear, surpise, contempt, and disgust. Confusion is not one of the universal expressions.

The facial feedback hypothesis states that facial expressions can actually trigger the appropriate emotion, rather than just being a reflection of that emotion. Therefore, a scenario that exemplifies that concept is that Thomas smiling (expression) made him feel happier (emotion).

Positive psychology is a growing field of psychological research that seeks to grow the empirical data on optimal human functioning and positive emotions (e.g., longitudinal happiness)