temperament
n. the basic foundation of personality, usually assumed to be biologically determined and present early in life, including such characteristics as energy level, emotional responsiveness, demeanor, mood, response tempo, behavioral inhibition, and willingness to explore. In animal behavior, temperament is defined as an individual’s constitutional pattern of reactions, with a similar range of characteristics. Studies of animals ranging from fish to nonhuman primates have documented differences in temperament, particularly along the shy–bold continuum. Within each population, there are individuals that show high levels of exploratory behavior toward novel features and others that appear to display neophobia.