ABSTRACT
Mental retardation can be traced, in a limited proportion of cases, to identified genetic factors, and in a larger proportion, with various degrees of certainty, to biological factors linked with various organic diseases, growth conditions, nutrition, etc. Modes of behavior characteristic of mental disease may be simply the result of a history of reinforcement, an unusual condition of deprivation or satiation, or an emotionally exciting circumstance. Even in cases in which genetic or other biological factors are likely or certain to be the cause of the psychological disorder, the behavioural approach to treatment remains important, as long as an effective biological treatment has not been discovered, and even after such treatment is available. Genetic engineering was still in its infancy when Burrhus Frederic Skinner first dealt with these problems, and in spite of the astonishing progress made since that time, it still does not have the solution to most genetically determined mental diseases.
