A whole lot of assumptions are being made in this thread. For a start, natural selection is about survival of the species and one assumption being made is that high IQ is going to be better for this. I think Douglas Adams made amusing comments about this in the "hitchhikers guide to the galaxy" when all the "useless people" were banished to another planet with a disasterous outcome. IQ tests are a measure of our ability to do IQ tests. As has been shown, and acknowledged in some comments above, IQ is not wholly governed (as was once believed by eminent psycholgists) by genetics but can be changed by quite a large extent by environment and education.



There has been much work on how to correlate simple tests (like IQ tests) with success in life, but I wonder to what extent we weight these tests with what we perceive as important today. I can think quite a few people who excel in their field of interest but are quite hopeless outside it and, in contrast, I can think of quite a few others who are generally very sensible and reliable but who do not have any outstanding talent. Both groups undoubtedly have a fairly wide IQ distribution and both groups are valuable and necessary in a working society.



It may be interesting to think how a society's demographics may be affected by a higher birthrate by sections of a community, but in discussing such issues it is worthwhile to try to step back and see these discussions from an "outside" perspective. Here are a bunch of reasonably high-IQ people discussing how their view of the future will change for the worse if nothing is done to give them a breeding advantage over the "lesser beings". How similar is this to the ideas of the late 19th and early 20th centuries which led to the ideas of eugenics and the resulting genocidal consequences?



As mudd1 says, we are probably approaching an era where we will be able to manipulate the genetic make-up of our offspring and that it will likely be yet another Pandora's box full of enabling, scientific advancement but without any ethical guidelines to go with it. I would not be confident that this will be of general advancement to the human race, at least not without setbacks, but I would agree it is likely to happen. It may be a measure of the quality of our society in how well such advances are handled. If such capability is limited and distibuted fairly we may have some chance of allowing more social interchange and reducing the problems resulting from class differentials. If it is something restricted in availability to those who can afford it, we are in danger of exacerbating problems and creating a more divergent social structure.