The ways in which personality and health interact are myriad and complex. Does personality predispose us to certain diseases? Does disease lead to changes in personality? The original formulation of psychosomatic medicine sought a direct link between personality and health – anxiety and hypertension, depression and cancer – and was largely unfruitful. Current research seeks to clarify how personality is associated with health-related behaviours like smoking and exercise, which put people at risk for disease. By elucidating the link between personality and health behaviours, the field makes substantive contributions to both patient treatment and public health prevention and intervention programmes aimed at reducing the incidence and prevalence of disease.

Personality as traits

For most of history, scholars and laypersons alike viewed human beings as rational creatures with propensities, abilities and beliefs that guided their conduct. Early in the twentieth century, this view was supplanted by psychoanalysis and behaviourism which characterized personality in radically different ways: for psychoanalysts, the essence of the person was in unconscious and often irrational processes; for behaviourists, the person was no more than a collection of learned responses to environmental reinforcements. Contemporary research has in turn rejected these two extreme views of personality and returned to a more commonsense approach, in which familiar traits such as persistence and sociability are seen as important determinants of behaviour.

It does not follow, however, that personality psychology is nothing but common sense.