# Humans are Becoming Genetically Less Intelligent
**URL:** https://boards.straightdope.com/t/humans-are-becoming-genetically-less-intelligent/320863
**Category:** Great Debates
**Created:** [September 9, 2005, 7:15pm UTC](https://boards.straightdope.com/t/humans-are-becoming-genetically-less-intelligent/320863 "2005-09-09T19:15:18Z")
**Posts on this page:** 20
**Page:** 1
### Author:  [@Asian-American](https://boards.straightdope.com/u/Asian-American)
#### Post date: [September 9, 2005, 7:15pm UTC](https://boards.straightdope.com/t/humans-are-becoming-genetically-less-intelligent/320863/1 "2005-09-09T19:15:18Z")
**1.** Human intelligence is largely hereditary.
**2.** Civilization depends totally upon innate intelligence. Without innate intelligence, civilization would never have been created. When intelligence declines, so does civilization.
**3.** The higher the level of civilization, the better off the population. Civilization is not an either-or proposition. Rather, it’s a matter of degree, and each degree, up or down, affects the well-being of every citizen.
**4.** At the present time, we are evolving to become less intelligent with each new generation. Why is this happening? Simple: the least-intelligent people are having the most children.
**5.** Unless we halt or reverse this trend, our civilization will invariably decline. Any decline in civilization produces a commensurate increase in the collective “misery quotient.”
Logic and scientific evidence stand behind each statement listed above.
Source: [http://www.eugenics.net/](http://www.eugenics.net/)
So, what are your thoughts?
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### Author:  [@John\_Mace](https://boards.straightdope.com/u/John_Mace)
#### Post date: [September 9, 2005, 7:25pm UTC](https://boards.straightdope.com/t/humans-are-becoming-genetically-less-intelligent/320863/2 "2005-09-09T19:25:41Z")
> [@Asian-American](#):
>
> At the present time, we are evolving to become less intelligent with each new generation. Why is this happening? Simple: the least-intelligent people are having the most children.
This is probably the weakest\* part of your argument. First, we’d need a cite that proves the final sentence. You are assuming “lower socio-economic class” = “less intelligent”. Unclear that that is true.
But let’s assume that is correct. It’s not the average intelligence of the group that keep civilization afloat, it’s the peak intelligence of the group. And since the smart guys are still have babies, and passing their intelligence on to the next generation, the peak intelligence of the group is not declining.
\*the real weakest part is that we know what intelligence is and that we can measure it. That is simply not true.
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### Author:  [@Larry\_Borgia](https://boards.straightdope.com/u/Larry_Borgia)
#### Post date: [September 9, 2005, 7:30pm UTC](https://boards.straightdope.com/t/humans-are-becoming-genetically-less-intelligent/320863/3 "2005-09-09T19:30:08Z")
> [@](#):
>
> 1. Human intelligence is largely hereditary.
cite please.
> [@](#):
>
> 1. Civilization depends totally upon innate intelligence. Without innate intelligence, civilization would never have been created. When intelligence declines, so does civilization.
What do you mean by innate intelligence?
> [@](#):
>
> 1. The higher the level of civilization, the better off the population. Civilization is not an either-or proposition. Rather, it’s a matter of degree, and each degree, up or down, affects the well-being of every citizen.
You’re right. The better off we are, the better off we are.
> [@](#):
>
> 1. At the present time, we are evolving to become less intelligent with each new generation. Why is this happening? Simple: the least-intelligent people are having the most children.
Actually there’s some evidence that we’re becoming more intelligent
[http://pespmc1.vub.ac.be/FLYNNEFF.html](http://pespmc1.vub.ac.be/FLYNNEFF.html)
> [@](#):
>
> 1. Unless we halt or reverse this trend, our civilization will invariably decline. Any decline in civilization produces a commensurate increase in the collective “misery quotient.”
But the trend doesn’t actually exist, so we don’t have anything to worry about. Phew, crisis averted! Return to your regularly scheduled activities, folks.
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### Author:  [@marshmallow](https://boards.straightdope.com/u/marshmallow)
#### Post date: [September 9, 2005, 7:34pm UTC](https://boards.straightdope.com/t/humans-are-becoming-genetically-less-intelligent/320863/4 "2005-09-09T19:34:54Z")
> [@Asian-American](#):
>
> 1. Human intelligence is largely hereditary.
I’d like to see the “logic and scientific evidence” for this assertion. I thought genetics and environment both play large roles but you couldn’t say that either one is the most important (barring extreme cases like genetic disorders or being locked in a closet and abused as a baby).
I also agree with Mr. Mace on all points.
Also…eugenics? I mean, you’re just asking for it linking to a site like that.
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### Author:  [@Larry\_Borgia](https://boards.straightdope.com/u/Larry_Borgia)
#### Post date: [September 9, 2005, 7:40pm UTC](https://boards.straightdope.com/t/humans-are-becoming-genetically-less-intelligent/320863/5 "2005-09-09T19:40:27Z")
[Wikipedia](http://en.wikipedia.org/wiki/Flynn_effect) on the Flynn effect, FWIW.
Also[Here’s](http://www.eugenics.net/papers/caseforeugenics.html) what I think the OP meant to link to. I’m sorry, but once you get phrases along the lines of “The liberal media are suppressing the terrifying truth” my BS meter goes into overdrive.
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### Author:  [@John\_Mace](https://boards.straightdope.com/u/John_Mace)
#### Post date: [September 9, 2005, 7:43pm UTC](https://boards.straightdope.com/t/humans-are-becoming-genetically-less-intelligent/320863/6 "2005-09-09T19:43:46Z")
> [@mstay](#):
>
> I’d like to see the “logic and scientific evidence” for this assertion. I thought genetics and environment both play large roles but you couldn’t say that either one is the most important (barring extreme cases like genetic disorders or being locked in a closet and abused as a baby).
I think the assertion is self-evident. If intelligence weren’t hereditary, all animals with brains would have an equal level of intelligence. IOTW, how did we become as intelligent as we are if not through adaptation-- ie, passing on benefitial traits.
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### Author:  [@Larry\_Borgia](https://boards.straightdope.com/u/Larry_Borgia)
#### Post date: [September 9, 2005, 7:46pm UTC](https://boards.straightdope.com/t/humans-are-becoming-genetically-less-intelligent/320863/7 "2005-09-09T19:46:25Z")
Sorry to keep barging in but [this link](http://www.bostonreview.net/BR20.6/block.html) **Agramn** posted in [thread=333697]this thread[/thread] right down the page is pretty useful, if hard going.
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### Author:  [@OliverTwistofLime](https://boards.straightdope.com/u/OliverTwistofLime)
#### Post date: [September 9, 2005, 7:47pm UTC](https://boards.straightdope.com/t/humans-are-becoming-genetically-less-intelligent/320863/8 "2005-09-09T19:47:41Z")
Let’s drop the term IQ and utilize more realistic phraseology that is inventions, new products, discoveries that benefit mankind.
Asian Americans and Jews for example play a large part in encouraging education and what comes out the funnel.
People around the world who live in poverty or have children by the carloads are far less likely to be productive in life.
Unfortunately the birthrate of the cultures that foster education is far less than the birthrate of the poor and less educated…Hence, in time the productive individual will decrease in numbers.
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### Author:  [@E-Sabbath](https://boards.straightdope.com/u/E-Sabbath)
#### Post date: [September 9, 2005, 8:12pm UTC](https://boards.straightdope.com/t/humans-are-becoming-genetically-less-intelligent/320863/9 "2005-09-09T20:12:28Z")
Amazingly enough, I have a cite that suggests the opposite.
[http://www.suntimes.com/output/news/cst-nws-brain09.html](http://www.suntimes.com/output/news/cst-nws-brain09.html)
The human brain is still evolving, changing rapidly.
Who’da thunk it?
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### Author:  [@E-Sabbath](https://boards.straightdope.com/u/E-Sabbath)
#### Post date: [September 9, 2005, 8:16pm UTC](https://boards.straightdope.com/t/humans-are-becoming-genetically-less-intelligent/320863/10 "2005-09-09T20:16:54Z")
Weird, that link worked for me… but not through the post. Try this one.
> **[Human brain still evolving study suggests](https://www.chron.com/news/nation-world/article/Human-brain-still-evolving-study-suggests-1506219.php)**
>
> WASHINGTON - The human brain may still be evolving. So suggests new research that tracked...
Anyhow, your suggested statement certainly is nothing new. Kornbluth thought of it in the 50s, with his celebrated Marching Morons.
The problem with it is that it’s not new, I’ve seen comments of that sort going back a few hundred years, and… well, the rich get richer, the poor have children. And somehow, we seem to be at least as smart as those greek fellers.
You seem to think that poor people are inherently less smart than rich ones? Are they?
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### Author:  [@RickJay](https://boards.straightdope.com/u/RickJay)
#### Post date: [September 9, 2005, 8:22pm UTC](https://boards.straightdope.com/t/humans-are-becoming-genetically-less-intelligent/320863/11 "2005-09-09T20:22:57Z")
If the OP is in any way accurate it should be quite easy to prove, what with IQ tests having been around for a century.
Darned Flynn Effect.
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### Author:  [@Darwins\_Finch](https://boards.straightdope.com/u/Darwins_Finch)
#### Post date: [September 9, 2005, 8:28pm UTC](https://boards.straightdope.com/t/humans-are-becoming-genetically-less-intelligent/320863/12 "2005-09-09T20:28:01Z")
> [@Asian-American](#):
>
> **1.** Human intelligence is largely hereditary.
What you meant to say was that “_variations_ in human intelligence are largely hereditary”. Since social Darwinism relies on the process being examined being so examined in the light of natural selection, it is those variations that are important, as they constitute the pool upon which selection operates. And those variations, not just the raw trait, need to be heritable.
As **John** observes, that intelligence is hereditary is a (heh) no-brainer. That variations in intelligence are largely hereditary is much more complicated. Unless that can be sufficiently demonstrated, the rest of your thesis falls apart.
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### Author:  [@marshmallow](https://boards.straightdope.com/u/marshmallow)
#### Post date: [September 9, 2005, 8:45pm UTC](https://boards.straightdope.com/t/humans-are-becoming-genetically-less-intelligent/320863/13 "2005-09-09T20:45:35Z")
> [@John Mace](#):
>
> I think the assertion is self-evident. If intelligence weren’t hereditary, all animals with brains would have an equal level of intelligence. IOTW, how did we become as intelligent as we are if not through adaptation-- ie, passing on benefitial traits.
> [@Darwin's Finch](#):
>
> As John observes, that intelligence is hereditary is a (heh) no-brainer. That variations in intelligence are largely hereditary is much more complicated. Unless that can be sufficiently demonstrated, the rest of your thesis falls apart.
Yes, I was speaking of the variations within human intelligence. This all leads to the nature/nuture debate, where it appears for some reason the OP falls squarely on the nature side of the debate. Unless I haven’t been reading the right publications, is it not still a healthy mix of both with the idea that we all have a potential range we can fall which depends on our environment? I imagine I would be much worse off if I grew up in poverty with a lack of quality education and good ol’e book learin’.
Then there’s the Flynn Effect, as **Larry** and **Rick** pointed out.
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### Author:  [@Hampshire](https://boards.straightdope.com/u/Hampshire)
#### Post date: [September 9, 2005, 9:18pm UTC](https://boards.straightdope.com/t/humans-are-becoming-genetically-less-intelligent/320863/14 "2005-09-09T21:18:40Z")
> [@Asian-American](#):
>
> **4.** At the present time, we are evolving to become less intelligent with each new generation. Why is this happening? Simple: the least-intelligent people are having the most children.
How about survival of the fittest? Surely a more intelligent person has a better chance of survival in the world.
More intelligent people may seek safer white-collar jobs in offices while less intelligent people may stay in jobs that carry risks (assembly line workers, coal miners, construction work, military).
More intelligent people have the means and intelligence to live healthier lives. More expensive healthy foods, fitness machines and/or memberships, safer neighborhoods versus cheap unhealthy fast food, unsafe neighborhoods.
(This all of course assuming that un-intelligence is related to poverty).
The longer you survive the longer you have to procreate.
Not to mention the human/animal instinct to mate with a partner who will give your offspring the greatest chance of survival.
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### Author:  [@Squink](https://boards.straightdope.com/u/Squink)
#### Post date: [September 9, 2005, 9:32pm UTC](https://boards.straightdope.com/t/humans-are-becoming-genetically-less-intelligent/320863/15 "2005-09-09T21:32:28Z")
[Human Brains Are Getting Larger, More Complex, Scientists Say](http://www.bloomberg.com/apps/news?pid=10000087&sid=azKGXNkD4Yeg&refer=top_world_news)
> [@](#):
>
> Scientists studying two genes that regulate brain size, Microcephalin and ASPM, found groups of variants, known as haplogroups, that emerged about 37,000 years ago and 5,800 years ago, according to the papers published yesterday in Science. Anatomically modern humans evolved about 200,000 years ago.
[More detail here](http://johnhawks.net/weblog/reviews/genetics/brain/lahn_2005_aspm_microcephalin_science.html)
> [@](#):
>
> Haplogroup D for Microcephalin apparently came under selection around 37,000 years ago (confidence limit from 14,000 to 60,000 years ago).
> …
> If the effect of the allele is additive or dominant, this selective advantage would be on the order of 2 or 3 percent – an advantage in reproduction.
> …
> The story for ASPM is similar, but even more extreme. Here, the selected allele came under selection only 5800 years ago
> …
> to come to its present high proportion in some populations of near 50 percent in such a short time, its selective advantage must have been very strong indeed – on the order of 5 to 8 percent.
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### Author:  [@foolsguinea](https://boards.straightdope.com/u/foolsguinea)
#### Post date: [September 9, 2005, 9:55pm UTC](https://boards.straightdope.com/t/humans-are-becoming-genetically-less-intelligent/320863/16 "2005-09-09T21:55:21Z")
> [@Asian-American](#):
>
> **1.** Human intelligence is largely hereditary.
Yes, it is. The intelligence of a housecat will not equal that of a healthy man, whatever the cat’s training. But here’s the fun thing about human genetics. The genes that allow for human intelligence are there in the gene pool, even among idiots. The variation in human intelligence is not that great between the obviously stupid & the apparently smart, nor is that variation likely to be more than half genetic.
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### Author:  [@Marley23](https://boards.straightdope.com/u/Marley23)
#### Post date: [September 9, 2005, 10:41pm UTC](https://boards.straightdope.com/t/humans-are-becoming-genetically-less-intelligent/320863/17 "2005-09-09T22:41:32Z")
I suppose that, strictly speaking, the Flynn Effect doesn’t prove that people are becoming more intelligent - just that with better nutrition and such things, more people are able to maximize whatever they have. But I thought “Flynn Effect” when I saw the OP, and I think **Squink** ’s cite is very interesting.
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### Author:  [@ITR\_champion](https://boards.straightdope.com/u/ITR_champion)
#### Post date: [September 10, 2005, 12:52am UTC](https://boards.straightdope.com/t/humans-are-becoming-genetically-less-intelligent/320863/18 "2005-09-10T00:52:54Z")
To quote from the link provided in the OP:
> [@](#):
>
> It is impossible here to review the voluminous evidence showing that racial-ethnic differences in intelligence are the rule rather than the exception (some groups performing better than whites and others worse), and that the well-documented black-white gap is especially striking.
Now why, pray tell, is it impossible to review such voluminous evidence? If such evidence actually existed, a quick review would be easy. If the evidence were truly voluminous, then it would be all the easier. All you would need to do is pick the most clear and succinct piece from this voluminous evidence, and there’s your review. If reviewing within the article itself would take too much space, you could at least list some of the voluminous evidence in the bibliography. But wait, the article that I was reading did not have any bibliography, which is mighty strange for any author who wants to be taken seriously as a scientist.
I can’t clame to be an expert on genetics or mental development or any related field. However, I have followed the debate about nature vs. nurture for the last ten years or so, and read a considerable number of articles on the topic. I am distinctly unimpressed by the “nature” side of the debate. Typically what happens is that the mainstream media will be flooded with articles reporting that scientists have found evidence that such and such a trait is genetically pre-determined. Upon digging deeper, one finds that the reported results are not nearly as firm as the articles suggest. Time goes by, and other reserachers are unable to duplicate the findings. But of course the press never reports this, so the public is left with the misconception that a scientific link between genetics and the trait in question has been established.
During my lifetime I’ve seen the media beguiled with stories about scientists claiming to have found the genes that determine everything from happiness to homosexuality to religious belief to (of course) intelligence. In all cases, the research doesn’t stand up to scrutiny.
It’s been over fifty years since we discovered DNA. We still are not capable of pointing to a single string of DNA in the human genome which produces above average intelligence. Just like physicists hunting for the ether in the 19th century eventually had to conclude that the ether wasn’t there, modern day geneticists will eventually need to realize that they’re unable to find the ‘genius gene’ because it doesn’t exist.
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### Author:  [@Tyrrell\_McAllister](https://boards.straightdope.com/u/Tyrrell_McAllister)
#### Post date: [September 10, 2005, 3:41am UTC](https://boards.straightdope.com/t/humans-are-becoming-genetically-less-intelligent/320863/19 "2005-09-10T03:41:33Z")
This is all very interesting, but my question is, why is the OP being so evasive about their own ethnicity?
[/sarcasm]
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### Author:  [@Bryan\_Ekers](https://boards.straightdope.com/u/Bryan_Ekers)
#### Post date: [September 10, 2005, 3:57am UTC](https://boards.straightdope.com/t/humans-are-becoming-genetically-less-intelligent/320863/20 "2005-09-10T03:57:09Z")
Actually, by identifying and eliminating/reducing from the environment certain destructive substances, like lead, he might not be evolving to be smarter but we are getting rid of things that were making us dumber, hence an overall improvement in human intelligence.
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