The movie Idiocracy was hardly academy award material, but it began with an interesting premise: Given that there is no strong selection for high IQ in the modern world, less intelligent people are having more children than are more intelligent people. Extrapolating that trend for 500 years, the movie's producers depicted a world populated by numbskulls. Is this a possibility?
There are several causes for concern. To begin with, it is a correct assumption that natural selection is largely agnostic with regard to intelligence. We large-brained hominids like to think that all the information-crunching power in our hypertrophied cortexes will eventually allow us to solve the big problems of modern times, allowing our descendants to persist into the distant future. But it ain't necessarily so. Dinosaurs were a lot smarter than cockroaches, and Australopithecines were Einsteinian by comparison, yet the roaches have had a much longer run, and are widely expected to outlast Homo sapiens.
And consider a few more historically local phenomena:
1. Even correcting for other factors, people living in larger families have lower IQs.
2. In the modern world, less educated people reproduce earlier, and have larger families than highly educated people.
3. Less educated people are more likely to hold conservative religious beliefs than are more educated people.
4. Conservative religiosity is associated with opposition to birth control and abortion. Jason Weeden has data suggesting this—is in fact close to the heart of the split between the liberal left and the conservative right.
5. Some conservative religions, such as the LDS church, actively encourage large families.
6. Other conservative religions, such as the Roman Catholic church, indirectly encourage large families by forbidding most means of family planning.
7. Larger families are likely to be poorer, and poverty triggers earlier puberty and earlier reproduction (a good deal of recent research suggests that this phenomenon is linked to biological life history patterns, and that it unfolds independent of any normative inputs from religions or local culture). All of these factors combine to ensure that poorer less educated young people are more likely to stay that way, and produce the next (slightly larger) generation of poor less educated young people.
8. Well-educated intellectual types have smaller families these days, and because highly educated women wait longer to begin reproduction, often miss their fertile window, and have no children.
During the 20th century, IQ tended to generally increase (a phenomenon dubbed the "Flynn Effect" after the researcher who discovered it). Various hypotheses have been advanced for this phenomenon, including better education and smaller families. But the factors I listed above could set a course in the opposite direction, flip-flopping the Flynn effect.
And there is another potential ironic twist. If the population of less educated religiously conservative individuals increases, and continues to vote as they have been voting, funding for education and scientific research is also likely to decrease. A less educated population could contribute not only to an upward shift in population size, but also to a downward economic spiral, for reasons linked to some fascinating findings by Heiner Rindermann and James Thompson.
These researchers examined the economic consequences of variations in a IQ across 90 countries, analyzing the average IQ of each country's population as a whole, as well as the average IQ of the "intellectual elite" (the top 5% of the population), and the lowest 5% of the population. Just as countries differ in their distribution of wealth, they also differ in their distribution of IQ. Canada and the U.S., for example, are identical in the IQ of their smartest people (120), but the lowest 5 percent of Canadians are 5 points smarter than the lowest 5 percent of Americans (75 vs. 80).
Rindermann and Thompson's analyses led them to this conclusion: Having a high IQ intellectual class—lots of people with accomplishments in science, math, technology and engineering—translated directly into more wealth for a country. To put it into purely economic terms, an increase of 1 IQ point among average citizens increases a country's average GDP by $229, whereas an increase of 1 IQ point in the intellectual elite is worth $468.
A high-performing intellectual class was also associated with better-developed and freer economic and political institutions, which in turn encouraged more development of the country's "cognitive resources," in what Rindermann and Thompson called a "virtuous cycle." The free climate becomes a catalyst for creative productivity among the high IQ innovators, who are thus liberated to rethink older ways of doing things, and to expand into new scientific arenas. This in turn inspires new technologies, as well as newer and more efficient ways of doing business, and a better climate in which to grow the next generation of innovators.
So to the extent that a growing anti-intellectual portion of the population manages to cut funds for education and for scientific research, they effectively cut off the system that feeds what has been the world's most productive "human capital" machine. According to my colleagues from other countries, the American educational system has a reputation as unimpressive up through the university level, but is regarded as the top of the heap when it comes to training at the highest level—with people around the world desperate to come to the United States to get the best Ph.D training on the planet. Thus, slashing funding for higher education and scientific research (much of which is conducted by our best Ph.D. students at major universities), seems like a policy destined to undermine the country's economic health in long-lasting ways.
Policies that undercut the intellectual upper crust therefore undermine economic growth, and indirectly contribute to the economic threat that inspires poorer less educated people to reproduce earlier and more prolifically.