The Pickering school held that blood pressure has a continuous distribution, that multiple genes and multiple environmental factors determine the level of one's blood pressure just as the determination of stature and intelligence is multifactorial, and that 'essential hypertension' is merely the upper end of the distribution (Pickering, 1978). In this view the person with essential hypertension is one who happens to inherit an aggregate of genes determining hypertension (and also is exposed to exogenous factors that favor hypertension). The Platt school took the view that essential hypertension is a simple mendelian dominant trait (Platt, 1963). McDonough et al. (1964) defended the monogenic idea. See McKusick (1960) and Kurtz and Spence (1993) for reviews. Swales (1985) reviewed the Platt-Pickering controversy as an 'episode in recent medical history.' The Pickering point of view appears to be more consistent with the observations.