Shame is a negative, painful, social emotion that "...results from comparison of the self's action with the self's standards...". Both the comparison and standards are enabled by socialization. Though usually considered an emotion, shame may also variously be considered an affect, cognition, state, or condition.The roots of the word shame are thought to derive from an older word meaning "to cover"; as such, covering oneself, literally or figuratively, is a natural expression of shame. Nineteenth century scientist Charles Darwin, in his book The Expression of the Emotions in Man and Animals, described shame affect as consisting of blushing, confusion of mind, downward cast eyes, slack posture, and lowered head, and he noted observations of shame affect in human populations worldwide. He also noted the sense of warmth or heat (associated with the vasodilation of the face and skin) occurring in intense shame.A "sense of shame" is the consciousness or awareness of shame as a state or condition. Such shame cognition may occur as a result of the experience of shame affect or, more generally, in any situation of embarrassment, dishonor, disgrace, inadequacy, humiliation, or chagrin.A condition or state of shame may also be assigned externally, by others, regardless of one's own experience or awareness. "To shame" generally means to actively assign or communicate a state of shame to another. Behaviors designed to "uncover" or "expose" others are sometimes used for this purpose, as are utterances like "Shame!" or "Shame on you!" Finally, to "have shame" means to maintain a sense of restraint against offending others (as with modesty, humility, and deference) while to "have no shame" is to behave without such restraint (as with excessive pride or hubris).