Foulds' “Continuum of Personal Illness” and the 16 P.F.

Foulds (1965) proposed that the classes of psychiatric illness can be described in terms of a continuum of increasing degrees of failure to maintain or establish mutual personal relationships. This concept of all psychiatric illness as an “illness of the person” centres on processes which occur in the mentally ill that interfere with the satisfactory establishment and relative endurance of adequate personal relationships. Foulds conceptualizes these interfering processes as barriers to achieving “personhood”: they may present as signs or symptoms of psychiatric illness or as abnormal degrees of personality traits. Thus, for example, cognitive disorder would make the schizophrenic unable to cope with the demands of interpersonal situations. Similarly, egocentricity would render the psychopath incapable of empathy and with a tendency to treat “others as objects or as organisms than as persons”. In both examples social alienation is inferred, manifested in the first case as withdrawal and in the second case as rejection. It is Foulds' thesis that this incapacity for mutual relations increases along a continuum from normality, through the personality disorders, neurosis, integrated psychosis (melancholics, manics and paranoids) to non-integrated psychosis (the schizophrenics).