Agreeableness is a personality trait manifesting itself in individual behavioral characteristics that are perceived as kind, sympathetic, cooperative, warm, frank, and considerate. In contemporary personality psychology, agreeableness is one of the five major dimensions of personality structure, reflecting individual differences in cooperation and social harmony.

People who score high on this dimension are empathetic and altruistic, while a low agreeableness score relates to selfish behavior (often manifesting as stinginess) and a lack of empathy. Those who score very low on agreeableness show signs of dark triad behavior such as manipulation and competing with others rather than cooperating.

Agreeableness is considered to be a superordinate trait, meaning that it is a grouping of personality sub-traits that cluster together statistically. The lower-level traits, or facets, grouped under agreeableness are: trust, straightforwardness, altruism, compliance, modesty, and tender-mindedness.