Defensive behavior is defined as that behavior which occurs when an individual perceives threat or anticipates threat in the group. The person who behaves defensively, even though he also gives some attention to the common task, devotes an appreciable portion of his energy to defending himself. Speech or other behavior which appears evaluative increases defensiveness. If by expression, manner of speech, tone of voice, or verbal content the sender seems to be evaluating or judging the listener, then the receiver goes on guard. Descriptive speech, in contrast to that which is evaluative, tends to arouse a minimum of uneasiness. Speech which is used to control the listener evokes resistance. In most of our social intercourse someone is trying to do something to someone else—to change an attitude, to influence behavior, or to restrict the field of activity.