The personality assessment literature using deviant and antisocial subject populations contains an interesting anomaly -- that persons representing major criminal offense categories can be only weakly distinguished from one another by using standard scales of the best conventional inventories (e.g., the Minnesota Multiphasic Personality Inventory and the California Psychological Inventory). This may reflect the fact that existing inventories are designed principally to predict maladjustment or social competence, and most criminal groups tested are found to be equally maladjusted and socially immature. The construct of ego control is not strongly related to adjustment or competence, but rather appears to underlie preference for different life-styles and occupations. (Publisher abstract)