ABSTRACT
Knowledge of psychological genetics can help psychologists enormously in practical problems as well as in theoretical issues in personality. In driving the individuals of small mental capacity to aim at abstract studies beyond their constitutional powers they produced warped personalities, beset with an irremediable sense of inferiority, only vaguely aware of the source of their frustration and harbouring strong anti-social tendencies. The interaction of heredity with environment requires rather that psychologists ask in what way and to what extent inherited nervous and psychological conditions set limits to the influence both of education and of ‘the slings and arrows of outrageous fortune’ which express the debit side of environment. Constitutional is a vague term, but is used by most as the broadest term of all, covering all reactivities which are so ‘set’ through age that for practical purposes they are not susceptible to psychological environmental changes.
