A single personality measure may possess different degrees of validity for different populations. It is inaccurate to describe measure of personality as valid or invalid in a general or overall sense. Anxiety about aggression was measured by assessing the inhibitory socialization behavior of the mothers of 10-13 year old boys. The population difference examined in this study represented a difference in the conditions of learning to express aggressive responses and the resulting difference in anxiety about aggression. The validity of nonovert and overt measures of aggression can be more easily demonstrated for a group of boys who have low anxiety about aggression. 19 refs.