A stable, relatively permanent characteristic.

In psychology, trait describes a characteristic that is unchanging and predictable. For example, shyness is a trait that is usually stable in an individual's personality. Another example is talkativeness. A child who is talkative is likely to continue this characteristic throughout the various stages of development.

There are some temperamental traits that researchers believe to be innate—that is, the infant possesses a basis for developing the trait at birth.

Other traits are acquired through learning, such as the tendencies toward tidiness or untidiness. Determining whether a trait is inborn or acquired is difficult, and many psychologists and others study various human traits to gather evidence to help provide insight into this question.

Some researchers are interested in the acquired traits that enable an individual to function effectively in society. These traits, known as socially adaptive traits, enable the individual to participate in society as a member of a couple, family, club, school class, or sports team. Examples of these traits are cooperation, motivation, and willingness to share. The counterpart to socially adaptive traits, socially maladaptive traits, prevent the individual from effectively participating in groups. Examples of socially maladaptive traits are deception, antisocial behavior, and extreme selfishness.