At Big Think, we have been told by the managing editor, in a tone of considerable confidence:

Because intelligence is such a strong genetic trait, rapidly advancing genetics research could result in the ability to create a class of super-intelligent humans one-thousand times higher in IQ than today’s most brilliant thinkers.

Stephen Hsu, Vice-President for Research and Professor of Theoretical Physics at Michigan State University, believes we are only a decade away from identifying the many thousands of genetic variants that control for intelligence. These variants, called alleles, could then be selected for by the parents of a soon-to-be-conceived child, and possibly genetic engineering could be done on adults to boost their intelligence.

Orion Jones, “Genetic Engineering Will Create Super-Intelligent Humans Within a Decade” at Big Think (October 22, 2014)

We’ve heard such claims for future superintelligent AI and cyborgs. But, as with Star Trek’s Klingons, if you really believe in them, they are real for you. They may help shape your actions even though they do not exist in nature.

With human intelligence, we are back in the world we know. And in the world we know, a number of things are quite uncertain.

First, there are obvious problems like, how much is genetics and how much is environment? From MedLine: “Studies have not conclusively identified any genes that have major roles in differences in intelligence. It is likely that a large number of genes are involved, each of which makes only a small contribution to a person’s intelligence… A person’s environment and genes influence each other, and it can be challenging to tease apart the effects of the environment from those of genetics.” Recent genetic studies point to some genes but provide no clear guidance.

It gets more complex. The interaction between genetics and environment plays a big role in intelligence: “… the right question is not a question of Genes v. Environment, the right question is how do genes and environment interact to shape behavior?” (Psychology Today)

And then there’s the Flynn effect: “… people living in the United States were gaining a little more than 3 points per decade on tests of human intelligence.” James Flynn (1934–2020) attributed this effect to the greater opportunity that modern societies offer for abstract, problem-solving approaches to life.

The obvious question is, if we wanted to increase “intelligence,” what exactly would we do?

Science writer Tom Chivers, author of How to Read Numbers (2021) thinks culling less intelligent humans early on is one possible step:

And, right now, we can look at the genomes of embryos before they’re implanted during IVF. It’s already done for various diseases caused by single mutations – it’s called preimplantation genetic diagnosis. At the fertility clinic, a couple might have 10 or so viable embryos; the clinicians would test them all, and if one of them were to have the gene for cystic fibrosis or sickle-cell anaemia or Huntington’s disease, you throw that one away and implant one of the ones that doesn’t…

You could do exactly the same thing with intelligence. You could sequence the genomes of a couple’s embryos prior to implantation and select the one with the selection of SNPs most correlated to intelligence. And this is before we get onto the possibilities of actually editing the genome, with tools such as CRISPR

Tom Chivers, “Should we edit genes to boost IQ?” at Unherd (October 16, 2018)

He has little time for objections. “In any case, it’s going to happen whether we like it or not,” because China will do it.

Well, in modern history, totalitarian societies have done many things to improve the gene pool or breed the type of subjects wanted. For example, there has long been interest in human–chimpanzee hybrids — humanzees — and many claim that Soviet dictator Joseph Stalin approved such an experiment. Nothing came of the matter in any event — the male apes were expendable but the African hospitals wouldn’t provide women patients as test subjects.

From available knowledge, intelligence boost proposals have all the makings of either nothing or the next ethical train wreck.

You may also wish to read: Can science really engineer a bigger human brain? Computational neuroscientist Daniel Graham wonders why we would bother. There is no strict relationship between brain size and intellectual achievement. The human brain has actually been shrinking in the last 30,000 years, the same period that has also shown great intellectual achievements.