Heredity and Psycho-Analysis1

It is an old problem which I shall discuss with you this evening and throughout the ages mankind has discerned its importance. Shakespeare indicates it in his own unrivalled manner where he makes Prospero judge Caliban:

A devil, a born devil, on whose nature Nurture can never stick; on whom my pains, Humanely taken, are all lost, quite lost; And as with age his body, uglier grows, So his mind cankers. The Tempest it, IV, i, 188–92.

Here nature denotes hereditary endowment and nurture the influence exercised by environment, and, as regards the effects produced on such endowment by the surroundings, Prospero shows a pessimistic view concerning Caliban. It is a point of view which has also prevailed in science and which still dominates the minds of many investigators.

It is not difficult to show that an hereditary endowment may actually exercise a fatal influence on the course of the bearer's existence. One example has to suffice. Is it not fate if a man, either in his younger years or at a riper age, begins to show the symptoms of Huntington's disease, deteriorating in a way that cannot be checked? This sufferer's destiny is a grievous one. More and more the normal control of the motility by the ego is replaced by almost entirely contrary conditions: the disordered motility breaks loose, the ego becomes subjected to it, and no longer rules. In the case of mental diseases springing from some inherited factor, the conditions appear to be far more complicated. Although in most cases of the endogenous psychoses the co-responsibility of other factors for the outbreak of the psychosis cannot be denied, cases do occur in which the endowment seems to possess such penetrating power that it scarcely needs auxiliary causes and could justifiably be considered fate.

It is not only these marked psychotic conditions whose causality must be sought in hereditary endowment. As early as 1876, Sir Francis Galton felt justified in asking whether nurture could 'do anything at all bey