The Future of Man—Evolutionary Aspects 
The population explosion is making us ask the fundamental 
question—so fundamental that it is usually not asked at all— 
what are people for? Whatever the answer, whether to achieve 
greater efficiency or power, or, as I am suggesting, to find greater 
fulfilment, it is clear that the general quality of the world’s 
population is not very high, is beginning to deteriorate, and 
should and could be improved. It is deteriorating, thanks to 
genetic defectives who would otherwise have died being kept 
alive, and thanks to the crop of new mutations due to fall-out. 
In modern man the direction of genetic evolution has started to 
change its sign, from positive to negative, from advance to 
retreat: we must manage to put it back on its age-old course of 
positive improvement. 
The improvement of human genetic quality by eugenic 
methods would take a great load of suffering and frustration off 
the shoulders of evolving humanity, and would much increase 
both enjoyment and efficiency. Let me give one example. The 
general level of genetic intelligence could theoretically be raised 
by eugenic selection; and even a slight rise in its average level 
would give a markedincrease in the number of the outstandingly 
intelligent and capable people needed to run our increasingly 
complex societies. Thus a 1:5 per cent increase in mean 
genetic intelligence quotient (I.Q.), from 100 to 101-5, would 
increase the production of those with an I.Q. of 160 and over 
by about 50 per cent. 
How to implement a eugenic policy in practice is another 
matter. The effects of merely encouraging potentially well- 
endowed individuals to have more children, and vice versa, 
would be much too slow for modern psychosocial evolution. 
Eugenics will eventually have to have recourse to methods 
like multiple artificial insemination by preferred donors 
of high genetic quality, as Professor Muller emphasized a 
quarter of a century ago, and I re-emphasized in my recent 
Galton Lecture. Such a policy will not be easy to execute. 
However, I confidently look forward to a time when 
eugenic improvement will become one of the major aims of 
mankind. 
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