Biological Possibilities in the Next Ten Thousand Years 
Parents of large families have a somewhat lower mean intelli- 
gence rating than the general population. But intelligence 
quotients or other similar measures are only partly determined 
genetically. It may be that the genetical factors making for 
intelligence do not lower fertility, while the social ones do so. 
I think it probable that the level of innate factors making for 
intelligence is slowly declining; but this is far from certain. As 
Penrose has suggested!, genetical homoeostasis based on the 
higher fertility of heterozygotes may make it very difficult for 
selection to alter this mean level. What is more, we may expect 
changes in the direction of this selection in the near future?. 
The fourth question is almost equally hard to answer. As I 
have already said, we may expect a drastic reduction in the 
frequency of undesired abnormalities with simple genetical 
determination by the end of this century. But we have little 
notion of how to produce more superior people. Our descen- 
dants could of course use men judged superior as stud bulls. 
However, even if women were agreeable, many men would 
require a good deal of conditioning before they acted as such, 
or even as sperm donors. Voluntary Amphitryons would 
perhaps be rarer than Brewer and Muller have thought. The 
employment of a surrogate was apparently normal in ancient 
India. Pandu’s biological father was a mortal chosen for holi- 
ness and appointed because the legal father was not functional. 
Nor was Pandu himself. His five sons, the heroes of our great 
epic, the Mahabharata, were begotten on his wives by immor- 
tals. His junior wife Madri had the intelligence to invoke the 
Asvini (twin deities corresponding to Castor and Pollux) and 
produced twins herself. 
My friend G. C. Dash informs me that until recently the Jats, 
in northern India, along with ordinary fraternal polyandry, 
practiced eugenics as follows. A young man judged of out- 
standing merit for physique, courage, and other good qualities, 
was allowed access to all married women of a village. He was 
given a pair of gilded shoes which he left outside the door 
when performing his eugenic duties, to warn off any ordinary 
husband. After fifteen years or so, when his daughters became 
oon 
