In psychology, temperament is the innate aspect of an individual's personality, such as introversion or extroversion.
Temperament is defined as that part of the personality which is genetically based. Along with character, and those aspects acquired through learning, the two together are said to constitute personality.
Historically the concept was part of the theory of the humours, which had corresponding temperaments. It played an important part in premodern psychology, and was important to philosophers like Immanuel Kant and Hermann Lotze.
It has also inspired artists like Carl Nielsen, and Hindemith, whose music is featured in George Balanchine's ballet "The Four Temperaments." See also Keirsey Temperament Sorter.