Super-Intelligent Humans Are Coming

Thursday, October 23rd, 2014

Super-intelligent humans are coming, Stephen Hsu argues:

The Social Science Genome Association Consortium, an international collaboration involving dozens of university labs, has identified a handful of regions of human DNA that affect cognitive ability. They have shown that a handful of single-nucleotide polymorphisms in human DNA are statistically correlated with intelligence, even after correction for multiple testing of 1 million independent DNA regions, in a sample of over 100,000 individuals.

If only a small number of genes controlled cognition, then each of the gene variants should have altered IQ by a large chunk—about 15 points of variation between two individuals. But the largest effect size researchers have been able to detect thus far is less than a single point of IQ. Larger effect sizes would have been much easier to detect, but have not been seen.

This means that there must be at least thousands of IQ alleles to account for the actual variation seen in the general population. A more sophisticated analysis (with large error bars) yields an estimate of perhaps 10,000 in total.1

Each genetic variant slightly increases or decreases cognitive ability. Because it is determined by many small additive effects, cognitive ability is normally distributed, following the familiar bell-shaped curve, with more people in the middle than in the tails. A person with more than the average number of positive (IQ-increasing) variants will be above average in ability. The number of positive alleles above the population average required to raise the trait value by a standard deviation—that is, 15 points—is proportional to the square root of the number of variants, or about 100. In a nutshell, 100 or so additional positive variants could raise IQ by 15 points.

Given that there are many thousands of potential positive variants, the implication is clear: If a human being could be engineered to have the positive version of each causal variant, they might exhibit cognitive ability which is roughly 100 standard deviations above average. This corresponds to more than 1,000 IQ points.

Comments

  1. Bert E. says:

    The Chinese are at the forefront of this reputedly. They do not have moral restrictions on selective breeding of humans for positive traits.

    This doctor on talk radio a number of years ago suggested that this has been going on for some time or has been contemplated for some time. Breed two types of humans. One very smart and the other not so smart but docile enough to be controllable.

  2. Candide III says:

    He’s making a completely unwarranted assumption that the effect of additional alleles on IQ will be linear. Given the universal applicability of the law of diminishing returns, I’d be very surprised if this turned out the case.

  3. Gwern says:

    Candide III:

    How much has diminishing returns set in for various forms of plant and animal breeding (oil content, milk yield, meat yield, feed-to-meat conversion efficiency, growth rate)? Or for very long-term selection experiments like the E. coli experiment? Yes, maybe there’s some upper limit to human biology where diminishing returns sets in sharply, but given that there are thousands of variants influencing intelligence, no one has ever come close to having all of the good ones. (Imagine we could only manufacture +7SD humans instead of +10SD. Would that make much of a difference to how wrong people like you were?)

Leave a Reply