Behavior, conduct, deportment are comparable when denoting a person’s actions in general or on a particular occasion, so far as they serve as a basis of another’s judgment of one’s qualities (as character, temperament, mood, manners, or morals).
Behavior may be used in reference to a human being regardless of status (as in age, development, or social standing), for it need not imply consciousness of what one is doing.
Behavior may be thought of as instinctive or as voluntary and, hence, as either a spontaneous expression of personality or character or as the result of training or breeding.
Since behavior is increasingly used in the various sciences in reference to animals and even substances, the term as referred to human beings tends in present usage to become more sharply differentiated from conduct than in the past. The latter term consistently carries a hint of moral responsibility and is less likely to confuse or mislead than behavior when this thought is prominent; thus, one dismisses a servant because of his conduct (better than behavior because it implies violation of principles).
Deportment (see also BEARING) is often used of behavior as taught or as the result of discipline; its strongest implication is that of degree of conformity to the accepted code of good manners or the conventions governing one’s relations to one’s fellows, one’s superiors, or one’s inferiors.