John Price

THE DOMINANCE HIERARCHY AND THE EVOLUTION OF MENTAL ILLNESS

Abstract In our evolution, we passed through a stage in which small social groups were regulated by strict dominance hierarchy, much as now exists in societies of baboons and macaques. For their stability, hierarchies require certain behaviour patterns from their members: irritability towards inferiors, anxiety towards superiors, elation on going up the hierarchy and depression on going down. Because of the great survival advantage to the group which a well-functioning hierarchy provides, these behaviour patterns have been strongly selected for. Equilibrium was reached when the advantage they provided was balanced by the disadvantage of excess of such behaviour. These excesses are manifested as mental illness; excesses of stable dominance hierarchy behaviour as the chronic illnesses such as anxiety neurosis, schizophrenia, and aggressive personality; and excesses of the behaviour associated with changes in the hierarchy as the phasic mental illnesses such as mania and depressive psychosis. The main prediction from the hypothesis is that factors which increase or reduce dominance hierarchy behaviour will have malignant or beneficial effects on mental illness. The main factor increasing such behaviour is instability in the hierarchy. The behaviour is reduced by strict control of the hierarchy from above, or by aggressive involvement with another social group. From general observation on man, it would also appear that alcohol (and other sedative drugs) and emotions akin to that of a religious love are powerful inhibitors. It is hoped that a psychiatric formulation of the hypothesis, which has been advocated in various forms by ethologists for many years, will give a stimulus to research on dominance hierarchy behaviour in animals and man.

Personality differences within families: Comparison of adult brothers and sisters.

313 pairs of brothers and 296 pairs of sisters were compared by one or both parents in a postal questionnaire. For 495 pairs independent questionnaires were completed by father and mother, and agreement between parents was good. There was a marked tendency for the first-born child to be rated as less fond of cuddling; he was also easier to train, worked harder at school, set himself higher standards, and was more serious, methodical, law-abiding, tidy and less impulsive; he learned to talk and read at a younger age and was rated as having more natural ability at schoolwork. These three groups of first-born attributes were relatively independent; for instance, even the first-born with less ability at schoolwork were given more responsibility at school. In the 152 pairs which did not contain a first-born, little birth order effect could be found, whether or not the elder was the eldest of his or her sex. There was a slight tendency for the broader, fatter and more muscular child to be less nervous and highly strung, but otherwise differences in physique were not related to differences in behaviour. Abilities at schoolwork, games, music and painting were not related. Tendency to anxiety and depression was related to lack of sociability; to stubbornness and lack of practicality; to angryness but not the bottling up of anger; to level of aspiration but not the possession of abilities or good looks. These relations of anxiety and depression in a normal sample closely parallel the items which distinguish psychiatric patients from their healthy siblings.

A twin study of graphology

The object of the study was to make an objective assessment of the validity of ascertaining personality from handwriting. The subjects chosen for the research were twenty-four pairs of identical and twenty-four pairs of non-identical twins. Personality scores were obtained from each subject, and each pair of twins was rated by their parent(s) on a questionnaire comparing their personality and development. These ratings were compared with ratings of within-pair personality differences based on the examination of samples of handwriting by a consultant graphologist and by a team of eight amateurs. The results showed that handwriting is not likely to be helpful in the study of neuroticism and is of no value in the determination of zygosity. In the case of extraversion, however, the correlations were low but in the expected direction and with reasonably good internal consistency.