ABSTRACT
Temperament conventionally refers to stable behavioral and emotional reactions that appear early and are influenced in part by genetic constitution. A temperamental category refers to a quality that varies among individuals, is moderately stable over time and situation, is under some genetic influence, and appears early in life. To posit a small number of basic temperaments—or personality types—is analogous to stating that the only two basic childhood illnesses are disorders of the gastrointestinal and respiratory tracts. A temperamental category is a changing but coherent profile of behavior, affect, and physiology, under some genetic control, that emerges in early childhood. Corticotropin releasing hormone (CRH), produced primarily in the paraventricular nucleus of the hypothalamus, is a second molecule relevant to temperament, for it has diverse influences, most of them excitatory. The most popular source of information on children's temperaments comes from asking parents, most often mothers, to describe or to rate their children on a variety of observable behaviors.
