“Eugenics is the science which deals with all influences that improve the inborn qualities of a race; also with those that develop them to the utmost advantage”. This was written by Sir Francis Galton, one of the founders of human genetics, in 1904. It represents the attitude of a scientist, more interested in finding out than in the application of his discoveries. In honour of Galton a Chair of Eugenics was established by the University of London at University College, with a strictly scientific orientation. Eugenical societies, founded in the USA and in Britain, with mainly social aims, have tended in recent years to become more and more scientific and research minded, and have renamed their journals as "Social Biology", and the "Journal of Biosocial Science".

   Nevertheless, for a long part of its history, "eugenics" is a word that has denoted a social programme, the improvement of mankind as a genetic stock. "Eugenic" laws, such as those that permit or enforce the sterilization of the mentally subnormal, have at some time been applied in a number of countries. Rigorous enforcement in Nazi Germany cast a slur on the whole concept of eugenics, which came to be regarded as incompatible with any humane or liberal attitude. The attack on eugenics, as a social programme, has been based on two main arguments: first, that "advantage", as used in Galton's statement quoted above, is itself undefinble; secondly, that the contribution from the genetical make‑up of an individual to his psychological and psychosocial aspects is negligible in comparison with the contribution of the environment. Furthermore, any interference with people's breeding habits has been looked on as a form of tyranny. From the scientific side, human geneticists have seen but little biological advantage to be drawn from eugenic social programmes, so that they have become increasigingly unwilling to defend them.

   Eugenics is thought of as operating in either of to directions, positive and negative. The sterilization laws of some States of the USA and of some European countries, were conceived as valuable contributions to negative eugenics, i.e. as measures which might help to reduce the incidence of illness and abnormality. The Utopian idea of improving the human stock has now largely lost its appeal; and investigations have shown that deviant individuals, the mentally subnormal, those subject to psychotic illness, etc., have reduced biological ‘fitness’, i.e. do not reproduce themselves (even in modern protective societies) proportionately with normal individuals. Natural selection, in fact, is still going on, which relieves us from the fear that the world will ever he overrun by excessive numbers of, say, schizofrenics or Huntington choreics. All wild species are able to carry a heavy "genetic load" of lethal and sub‑lethal genes without losing their racial vigour. If we want to get rid of phenylketonuria and Huntington's chorea, as surely our race will wish to do one day, this will not be for "eugenic" reasons, but to prevent human suffering. When the clin­ician suggests to a woman who has had a schizophrenic illness that, perhaps, it would be better not to have children, such advice will be given primarily for her own sake (because childbearing may be thought to carry with it a risk of relapse, or because rearing a family is particularly stressful for a woman of inpaired stability); or, perhaps, for the sake of those who would be her chil­dren, since any child born into this world would seem to have a natural right to affectionate and stable family life. No one now would be worried by the fear of spreading around the hypothetical schizophrenogenic gene or genes, though schizophrenics who are contemplating parentage should be informed of the enhanced risk of schizophrenia for any child they might have, in comparison with the general population.

   Positive eugenics, aiming to improve the human stock in respect of such qualities as health, vigour, intelligence, etc., has come to be regarded as even mor utopian. The only racial quality which geneticists are quite sure is advantageous is heterogeneity in genetic make‑up manifesting itself as variability phenotype. If one attempts to breed a stock in any particular direction (e.g. conceivably mankind, towards greater educability, or intelligence), then this will be at a cost in variability, and moreover at the cost of reducing variab­ility in respect of a large number of unknown or unrecognized genetically determined traits, as well as in the target feature.

  It sounds a noble ideale to purge mankind of its excessive stupidity, to multiply the incidence of men of genius, to improve the general average of mankind in the spread andstrength of mental abilities.Perhaps, if we had societeies in which talents were used to serve the community instead of the material interests of the individual himself, this ideal would be so attractive that we would start to think of ways in which certain breeding habits might be gently encouraged, and other as gently discouraged. Unfortunately, as things are, the exercise of mental abilities seems to lead, not to any cultural plus, but only to an advance in material prosperity. And prosperity now is under fire from the conservationists, whose first thought is for the total world environment.