I take intelligence to be a capability – a potential. For every human it is – by my definition – genetic. Knowledge, not intelligence, is what is acquired. No matter how we define it, intelligence is a composite consequence of many genes. Epigenetics suggests that some of these genes may be switched on or not depending upon nurture but the existence of the relevant genes must surely be inherited (nature). The supremely idiotic goings-on in Iraq and Syria and Gaza and Africa and in all the instances of barbarism and mayhem around the world are all consequent to a lack of intelligence. They only convince me that human intelligence is not on the increase and- clearly – is not a trait that is being selected for.
But it should be.
Though intelligence does seem to be positively correlated with survival to reproduction age, it seems that it leads to a lower reproduction rate which more than negates the effects of the increased survival. Assuming that IQ is at least a partial measure of intelligence, fertility rate seems to reduce with increasing intelligence. If the lower reproductive rate is actually a consequence of the higher intelligence, then the human race – without intervention – is doomed to remaining where it is on the scale of intelligence and its proportion of idiots. The paradox is that there is nobody who does not want to be more intelligent – but it does not seem to be an evolutionary trait.
IQ and fertility: A cross-national study
Many studies have found a small to moderate negative correlation between IQ and fertility rates. However, these studies have been limited to the United States and some European countries. The present study was a between-nation study using national IQ scores and national fertility rates. There were strong negative correlations found between national IQ and three national indicators of fertility.
“Evolution” is actually just the result of the those who failed to reproduce. So while intelligence may be a survival trait it does not seem to result in increasing reproduction and is therefore not an evolutionary trait.
Demographically then the human race – without human intervention – is condemned to a “dumbing down”.
Is human intelligence declining?
If “intelligence” is an inherited characteristic – as it seems at least partially to be – then it is only a matter of simple arithmetic that unless the “more intelligent” reproduce at a higher rate than those of “less intelligence” then the “average intelligence” of the population will inevitably decrease.
There is little doubt that there is a connection between intelligence and brain size. But brain size alone is not a measure of intelligence. Intelligence was probably selected for (and therefore an evolutionary trait) during the period when the size of the human brain was increasing. Possibly at some point the collateral genetic cost of increasing intelligence led to a leveling off. There could well have been trade-offs during the period when – simultaneously – food supply was more secure, human brain size was increasing, intelligence increased, language was evolving and social interaction was increasing. Quite possibly there is an optimum combination of these (and possibly other) traits for any given set of prevailing environmental conditions.
Brain size does not seem to have increased for anatomically modern humans (AMH) and that means for around 100,000 years – perhaps 200,000. But during this time the physical differences between the various “races” of humans have evolved. Possibly these physical changes have occurred fastest during the last 20,000 years since the end of the last glacial period. But even coping with this massive change of environmental surroundings has not led to the further development of brain size and – apparently – intelligence. There is some suggestion that intelligence peaked with the hunter-gatherers. Intelligence has not been a decisive factor for survival and subsequent reproduction. Perhaps human intelligence cannot increase unless the conditions first exist which lead to an increase of brain size? Or perhaps brain size increases only as a consequence of intelligence being selected for?
The question is whether we should now explicitly be trying to increase the intelligence of humankind?
We are now within a paradigm where “natural selection” by the prevailing environment has been decoupled from survival and subsequent reproduction. Natural selection is apparently obsolete and of no great value for the further development of humankind. Social factors rather than the surrounding environment control fertility. The welfare state has seen to it that physical disabilities after birth generally do not act as a de-selector. “Artificial selection” does not yet dominate but is of increasing importance in determining who survives to subsequently reproduce. Abortion (25 -30% of all conceptions) de-selects for some serious, detectable, physical disabilities but is also often for the social convenience of the mother. Surrogacy and IVF are driven by social needs and are providing the possibility of selecting for specific characteristics – though the “selection” is still largely hit-and-miss. I am not sure that IQ is necessarily the best measure of intelligence, but it seems ridiculous that where we do use “artificial selection”, intelligence is not also a criterion for selection.
Humans have learned to overcome the limitations of the surrounding “natural” environment. We cannot predict – let alone control – earthquakes and volcanoes, but we do build houses which make the vagaries of most weather irrelevant. We breed other species to suit our needs. We overturn the natural order of things by protecting the weak and healing the sick and caring for the old. Modern living is fundamentally “unnatural” in that it is dominated by human intervention to mitigate “natural” effects. The many deficiencies we still have – poverty and gratuitous violence and famine and rape and genocide and intolerance and religious insanities – can all be put down to insufficiency of intelligence.
There is nothing wrong with eugenics. It is the methods by which it is applied which can be ethical or unethical.It is inevitable that we try and achieve a growth of intelligence. And perhaps it has already started – in China.
iO9: Chinese parents will be able to engage in what’s called preimplantation genetic diagnosis (PGD) in order to select the most “intelligent” babies. It’s not genetic engineering — instead, doctors look at the DNA of several zygotes and choose the most promising one for implantation. Put this reproductive technology in the hands of enough parents, and the next generation of Chinese citizens could start to exhibit rates of intelligence five to 15 IQ points higher than what’s typically seen today.
China passed its so-called “Eugenics Law” in 1994, what it formally calls the “Maternal and Infant Health Care Law”:
This law regulates support for maternal and child health and also requires physicians to recommend a postponement of marriage if either member of a couple has an infectious, contagious disease or an active mental disorder. If one member of a couple has a serious hereditary disease, the couple may only marry if they agree to use longterm contraception or to undergo sterilization. If prenatal tests reveal that a fetus has a serious hereditary disease or serious deformity, the physician must advise the pregnant woman to have an abortion, and the law states that the pregnant woman “should” follow this recommendation.
The introduction of novel biotechnologies could allow the communist government to take its eugenic-like policies to the next level (though it’s not clear at this time if China will insist that PGD be enforced in this way). But rather than just screen for a “serious deformity,” the Chinese may eventually designate any kind of “deleterious” trait — like low IQ — as something that can and should be eliminated from the gene pool (with “low” IQ being a potentially normative and scalable characteristic).
Put that together with the Chinese Genetic Program:
Vice: At BGI Shenzhen, scientists have collected DNA samples from 2,000 of the world’s smartest people and are sequencing their entire genomes in an attempt to identify the alleles which determine human intelligence. Apparently they’re not far from finding them, and when they do, embryo screening will allow parents to pick their brightest zygote and potentially bump up every generation’s intelligence by five to 15 IQ points.
Related: On birth rates, abortions and “eugenics by default”