Current views on aggressive behaviour (Buss, 1961; Berkowitz, 1962) propose a direct relationship between the frequency and intensity of aggression, both of which are in turn considered to be related to extraverted personality patterns (Buss, 1961; Bendig, 1961). The frequency and intensity of aggressive responses, it is maintained, are both indications of the habit strength of the aggressive response. Such conclusions are derived from laboratory studies in which, for obvious reasons, intensity of response will not reach extreme proportions. However, studies of those who have indulged in extremely aggressive behaviour are not in accord with this view. Megargee and Mendelsohn (1962), for example, found that extremely assaultive criminals scored lower than nonviolent criminals and normals on personality scales related to hostility and lack of control, and more recently Megargee (1966) has reviewed the literature on this subject, which suggests that a large proportion of those who have committed crimes of extreme violence have no previous history of assaultive behaviour and are well controlled in their behaviour generally.