Handbook for speakers / issued by the Joint Committee on Voluntary Sterilization.

Date:
[1934?]
Catalogue details

Licence: Attribution-NonCommercial 4.0 International (CC BY-NC 4.0)

Credit: Handbook for speakers / issued by the Joint Committee on Voluntary Sterilization. Source: Wellcome Collection.

    19/40 (page 14)
    (i) The Standards by which mental deficiency is judged vary considerably. Though mental deficiency in general, and the various categories into which it has been divided, have received legal definitions in the Mental Deficiency Acts, the biological criteria by which it is appraised vary between wide limits. Many of the parents of mental defectives are retarded persons on the border-line which separates the dull normal from the certifiable defective. It is frequently difficult to decide whether such per¬ sons are to be counted as normal or defective. The Brock Report (para. 16) says, The fact that so many of the parents are border-line cases explains to a great extent the wide variations in the estimates given by various investigators of the proportion of parents who are mentally defective. A slight modi¬ fication of standard may result in a large increase in the number of persons regarded as mentally defective among these border¬ line cases. Clinically there is no definite line separating mental defect from dullness; the one condition merges gradually into the other. It is clearly very difficult to establish definitely what these standards are to be. (ii) Nobody has yet defined the degree of morbidity in a pedigree in which mental deficiency occurs which justifies the investigator in saying that the defect is the result of bad heredity. Investigators differ widely in the thoroughness with which they examine the parents and accessible living relatives of defectives; and they differ even more widely in the thoroughness with which information about the remoter ancestors and collateral relatives is sought. Thus, if the mother of a defective were herself defective, one could assert that the child's defectiveness was due to heredity with little fear of contradiction. But if a paternal uncle or grandparent or some more remote relative were defec¬ tive or exhibited some other pathological character such as insanity, epilepsy or habitual drunkenness, the causal significance of hereditary factors would be more difficult to establish. Allow¬ ances have also to be made for the size of the sibships^ of defec¬ tives and of their parents. The larger the sibship of the defective and of his parents and grandparents, the greater the chance of morbid traits latent in the strain manifesting themselves. The following generalisation is justified by a comparison of different investigations : the more carefully the parents are examined and the more widely the net is cast in examining the ascendants and collateral relatives of defectives, the greater is the rôle assigned to heredity. Speakers will often be asked what will be the racial effects of legalising voluntary sterilization ? ' How much will the inci- ^The word sib is a collective word denoting brothers and sisters in the same way that the word parents collectively denotes father and mother. 14