Emotion is a complex psychophysiological experience of an individual's state of mind as interacting with biochemical (internal) and environmental
Natural environment
The natural environment encompasses all living and non-living things occurring naturally on Earth or some region thereof. It is an environment that encompasses the interaction of all living species....

 (external) influences. In human
Humans are the only living species in the Homo genus...

s, emotion fundamentally involves "physiological arousal, expressive behavior
Behavior or behaviour refers to the actions and mannerisms made by organisms, systems, or artificial entities in conjunction with its environment, which includes the other systems or organisms around as well as the physical environment...

s, and conscious experience
Consciousness is a term that refers to the relationship between the mind and the world with which it interacts. It has been defined as: subjectivity, awareness, the ability to experience or to feel, wakefulness, having a sense of selfhood, and the executive control system of the mind...

." Emotion is associated with mood
Mood (psychology)
A mood is a relatively long lasting emotional state. Moods differ from emotions in that they are less specific, less intense, and less likely to be triggered by a particular stimulus or event....

, temperament
In psychology, temperament refers to those aspects of an individual's personality, such as introversion or extroversion, that are often regarded as innate rather than learned...

, personality
Personality psychology
Personality psychology is a branch of psychology that studies personality and individual differences. Its areas of focus include:* Constructing a coherent picture of the individual and his or her major psychological processes...

, disposition
A disposition is a habit, a preparation, a state of readiness, or a tendency to act in a specified way.The terms dispositional belief and occurrent belief refer, in the former case, to a belief that is held in the mind but not currently being considered, and in the latter case, to a belief that is...

, and motivation
Motivation is the driving force by which humans achieve their goals. Motivation is said to be intrinsic or extrinsic. The term is generally used for humans but it can also be used to describe the causes for animal behavior as well. This article refers to human motivation...

. Motivations direct and energize behavior, while emotions provide the affective component to motivation, positive or negative.

No definitive taxonomy
Taxonomy is the science of identifying and naming species, and arranging them into a classification. The field of taxonomy, sometimes referred to as "biological taxonomy", revolves around the description and use of taxonomic units, known as taxa...

 of emotions exists, though numerous taxonomies have been proposed.