The normal state of affairs, in human society, is for males to compete for females. The fact that more boys than girls are born (in every society) serves to intensify this competition. Though there is a tendency for excess boys to die off through war and rivalry, this only underscores the fact the the fittest males tend to be the ones who survive and reproduce.
When we look at world sex ratios, it becomes clear that low ratios (i.e. less of a predominance of boys over girls) are concentrated in sub-Saharan Africa. When examining such tables, it is important to consider the overall size of a population along with age distribution. For example, Granada only has 90,000 people and Lichtenstein only 34,000. Furthermore, 12% of the latter’s population is over 65; there are always more females than males amongst the elderly.
In contrast, China is heavily skewed toward males. My understanding is that this has been the case historically as well. India, on the other hand has, historically, been more balanced. Female infanticide was practiced mainly among the higher castes because higher caste females were not permitted to work outside the family. This was not the case among the lower castes, where women were required to work just like the men.
Sex ratios in Europe are similar to those in sub-Saharan Africa. It seems to me that the underlying causes are different. Modern Europe has a low sex ratio because of modernization and gender equality. Sub-Saharan Africa has a low sex ratio mainly because more girls are born to begin with. It is known that Medieval Europe (or, at least parts of Europe) had a very high sex ratio, sometimes as high as 253 men for every 100 women. Some have suggested female infanticide as a possible explanation.
When we look at these historical trends, scant as they are, and compare them to average I.Q.’s, a pattern emerges. When men have easy access to women over long periods of time, the average I.Q. of that population would fall. This does not bode well for modern Western society and it goes hand in hand with the backwardness of Africa.
What about American blacks? Blacks in America do not live in an isolated reproductive community. If they did, then it is likely that their average I.Q. would match that of sub-Saharan Africa (plus whatever European contribution they happen to have). Currently there is an artificial premium on black males. At the same time, countless non-black females are available to them – thus intensifying competition among black females for black males. Hence there is practically no selective pressure, among American blacks, for higher I.Q. in finding mates. On the contrary, there is selective pressure for lower I.Q. in reproducing; higher I.Q. blacks will tend to have less children, just like their white and Asian counterparts.
My prediction? White I.Q.’s are likely to stagnate. Chinese and Indian I.Q.’s will surge. American black I.Q. will plummet. Of course, India is unlikely to maintain its current anti-female practices for long; social unrest might force drastic changes before any I.Q.-boosting evolution can take place. The same is true for China, except that China has maintained this pattern for centuries, so its higher I.Q. is already a fait accompli.
As for sub-Saharan Africa, things will only get worse. As more intelligent African men migrate out of Africa, only the dullest will remain – and these remaining men will be like roosters in the hen house. The only way to prevent such a scenario would be to rapidly make African societies more attractive for successful men. This can only happen from within. African leaders have their work cut out for them.