Forget “Peak Oil” and “Peak Credit” … Are We On the Downslope of “Peak Intelligence”?


Scientists say that we have much smaller brains than our ancestors had 20,000 years ago … and we might have gotten stupider since agriculture became widespread.

Indeed, Huffington Post reports that we’ve probably gotten dumber than even our Victorian ancestors:

A provocative new study suggests human intelligence is on the decline. In fact, it indicates that Westerners have lost 14 I.Q. points on average since the Victorian Era.


As for Dr. te Nijenhuis and colleagues, they analyzed the results of 14 intelligence studies conducted between 1884 to 2004, including one by Sir Francis Galton, an English anthropologist and a cousin of Charles Darwin. Each study gauged participants’ so-called visual reaction times — how long it took them to press a button in response to seeing a stimulus. Reaction time reflects a person’s mental processing speed, and so is considered an indication of general intelligence.


In the late 19th Century, visual reaction times averaged around 194 milliseconds, the analysis showed. In 2004 that time had grown to 275 milliseconds. Even though the machine gauging reaction time in the late 19th Century was less sophisticated than that used in recent years, Dr. te Nijenhuis told The Huffington Post that the old data is directly comparable to modern data.

Other research has suggested an apparent rise in I.Q. scores since the 1940s, a phenomenon known as the Flynn Effect. But Dr. te Nijenhuis suggested the Flynn Effect reflects the influence of environmental factors — such as better education, hygiene and nutrition — and may mask the true decline in genetically inherited intelligence in the Western world.

This new research was published in the April 13 issue of Intelligence.

There are several theories for why we are getting dumber, including the following (the first 2 come from the HuffPost article):

(1) Dr. Jan te Nijenhuis points to the fact that women of high intelligence tend to have fewer children than do women of lower intelligence. This negative association between I.Q. and fertility has been demonstrated time and again in research over the last century.

(2) “The reduction in human intelligence … would have begun at the time that genetic selection became more relaxed,” Dr. Gerald Crabtree, professor of pathology and developmental biology at Stanford University, told The Huffington Post in an email. “I projected this occurred as our ancestors began to live in more supportive high density societies (cities) and had access to a steady supply of food. Both of these might have resulted from the invention of agriculture, which occurred about 5,000 to 12,000 years ago.”

(3)  Humans evolved to eat a lot of Omega 3s:

Wild game animals have much higher levels of essential Omega 3 fatty acids than domesticated animals. Indeed, leading nutritionists say that humans evolved to consume a lot of Omega 3 fatty acids in the wild game and fish which they ate (more), and that a low Omega 3 diet is a very new trend within the last 100 years or so.

In other words, while omega 3s have just now been discovered by modern science, we evolved to get a lot of omega 3s … and if we just eat a modern, fast food diet without getting enough omega 3s, it can cause all sorts of health problems.

So something just discovered by science can be a central fuel which our bodies evolved to use.

Omega 3s – in turn – boosts intelligence and help prevent cognitive decline.

(4)  Exercise boosts intelligence … and our ancestors got a lot more exercise than we do!

In addition, high levels of cortisol – the chemical released by the body when one is under continuous, unrelenting stress – and poverty can physically impair the brain and people’s ability to learn.

On the other hand, relaxing activities like meditation and prayer have been shown to increase brain mass and connectivity in certain areas of the brain.

Hunter-gatherers had more leisure time – and a more playful attitude – than we do today.

(5) Toxic chemicals in the environment can reduce intelligence.  Examples include flame retardantlead (found in many lipsticks), certain pesticides (and see this and this), and fluoride.

Category: Think Tank

Please use the comments to demonstrate your own ignorance, unfamiliarity with empirical data and lack of respect for scientific knowledge. Be sure to create straw men and argue against things I have neither said nor implied. If you could repeat previously discredited memes or steer the conversation into irrelevant, off topic discussions, it would be appreciated. Lastly, kindly forgo all civility in your discourse . . . you are, after all, anonymous.

25 Responses to “Is Modern Life Making Us Dumber?”

  1. Gonzop says:

    no need to go very far

    we invented the Kardashians

    reality TV is killing humanity, and the declining level of media content in general

  2. victornl says:

    Meh, reaction time seems to me a poor proxy for intelligence, Chimpanzees can solve puzzles faster than we do:
    In contrast to reaction time, as mentioned, actual IQ’s have been increasing over time, measured with IQ-tests:
    Larger brains are by no means a definite IQ increaser, Neanderthals had way bigger brains than we did (but were not smarter), it’s about the amounts of connections within the brain (the NASA supercomputer that sent a man to the moon in the sixties was way bigger, but much less powerful, than the smartphone computer in my pocket).

  3. Julia Chestnut says:

    The whole thesis hangs on the premise that visual reaction time is a “key indicator” of intelligence. HUH? There are a couple of reasons I can think of (no more fanciful than those listed here) why visual reaction speed might not be the kind of intelligence necessary in modern life, whereas it might have been critical to earlier ancestors. To my mind, processing speed really is just one part of intelligence anyway. I know and love someone diagnosed with slow processing speed who is a savant at matrix reasoning and puzzle solving. He’s not fast – he’s just extremely clever a bit more slowly. In modern life, as opposed to when reacting to constant warfare and predator interactions, I’m thinking this might be more useful. I guess what I’m saying is – yeah, that might be less in current humans than in the past. Is that because we’re selecting away from it for a reason?

    You can also have a smaller brain, without losing capacity, if the connections among neurons and how the brain uses space become more efficient. Given the costs of carrying around a huge cranial case, I would readily believe that has occurred over millennia. We know that in modern humans the paring process for learning we don’t use has become very efficient. In biological systems, as in computers over the past 40 years, smaller does not necessarily mean less capable.

    In short, lots of hypotheses sounds dumb while they are still half baked or the evidence is still coming in. But at this point, I call b*^&s%$#.

  4. TrainStation says:

    Our I.Q.s have dropped 14 points since the Victorian Age?

    This may explain why engineering schools are out of vogue and our law schools are swamped, and why we praise the Carl Levins (lawyer) and demonize the Tim Cooks (engineer) and the Steve Jobs. Back when we had brains we praised the Henry Fords and the George Westinghouses. Scary.

  5. Chad says:

    I agree with victronl. This is a very squishy experiment at best. Though, I must admit I am worried about the stupid breeding more than the intelligent.

    Just because someone chooses a profession is no reason to demonize or laud him/her. Under your scenario you would have to despise Mr. Ritholtz (lawyer by training). People don’t despise Cook or Jobs because of what their base training was in. No one says, “If only Cook was a lawyer, then I could respect him. But, an engineer? What an ass.”

    • TrainStation says:

      Despise people for their training? I didn’t say that. As for BR, he left law.

      But I do have a problem with our society attacking the doers and creators and for praising the attackers.

      • end game says:

        TrainStation, if you’re referring to the “doers and creators” in a Randian sort of way– the rich aren’t wealth creators, they’re wealth possessors. Some rich people create jobs, some don’t.

        If by “attackers” in our society you mean people who criticized the huge tax cuts the rich got from 2001 to 2012, then you’ll have to explain at what threshold level of taxation is so low for the rich that it’s no longer an “attack” but a legitimate question. A debate on 15% on carried interest is off-limits? Then what then is your “fair” level to contribute to our nation’s broad education, it’s military: 10? 5? 1%? 0%? Is any level too low to your way of thinking?

        You might also be giving too much credit to the “doers’ and creators’” advantages growing up. You give me one kid from the ghetto and let me educate them and then put them up against one of your doers and I’ll bet you’ll be surprised at the results. Better yet, let’s “trade places” between the two and see who your creator is now.

    • blackvegetable says:

      “Though, I must admit I am worried about the stupid breeding more than the intelligent.”

      The Marching Morons – Cyril Kornbluth

    • willid3 says:

      might be more that folks going to law school thought they had a better chance to earn more money? since engineers have a harder time doing that because its a lot easier to outsource engineers than lawyers. not that it hasnt been done, but you do see lot more pressure on engineers incomes from that than lawyers.

  6. BennyProfane says:

    “Even though the machine gauging reaction time in the late 19th Century was less sophisticated than that used in recent years, Dr. te Nijenhuis told The Huffington Post that the old data is directly comparable to modern data.”

    Uh, really? How so? You’re telling me that data from a machine operating in a time well before any sort of sophisticated devices have been developed is as reliable as such an instrument made and operated today? We’re talking milliseconds here, right?

    • end game says:

      Great point and I had the same thought but I still think there is something to this. For example, d
      on’t you feel in your gut that 50 years of kids watching cartoons has had some effect?

  7. econimonium says:

    Here is an interesting data point. I gave the exact exam I took in Comp Sci I in 1987, just changed to reflect the programming language (Pascal vs Java) but otherwise the same (yeah, no matter what you hear the bedrock concepts are still the same). Everyone failed. I got an A back then and as I recall, there weren’t actually any failures. The answers to long-form questions were also mostly grammatically appalling, and the questions featuring math problems (algebraic) were universally wrong.

    So in this not very scientific test above, coupled with my direct experience in being an adjunct teaching math and Comp Sci for a long time now, I squarely blame the educational system at the primary and secondary levels. It’s pretty easy to see, and all of us at the college level know about it but what do we do? Fail everyone? (My tactic is actually to get the worst ones to drop. It works because, frankly, I can’t help them at that point in their lives unless they go back and take fundamental subjects for a year or so). And I also blame parents because, God forbid, we give their children the grades they deserve. (Yes, I’ve had parents call me *at the college level* to complain and call my dean. We just read them the law that states we can’t discuss the child with them, if the child is 18 or older and hang up). So I don’t believe for a second it’s evolutionary. It’s completely and utterly environmental. If children don’t learn how to process as children, they get dumber. If they don’t learn how to react to various environmental situations they get dumber. If their parents insist of teaching them evolution is wrong, they get dumber. And it’s not having lower intelligence parents either because I’ve seen some pretty low intelligence parents raise some brilliant kids. But if the home environment isn’t conducive to exploration, mistake-making, risk-taking, and failure (everyone wins!! yey!!!) you get not very mentally active kids.

    • willid3 says:

      oddly enough my father who was teaching college math back in the 1970s had the same complaint about students back then. guessing that its more of a case that we now have tens of millions of students as opposed to maybe hundreds of thousands. but i do agree in that its mostly the parents that have more to do with how well their children get educated. if the parents dont really care, then why should their children? if parents can’t see any benefit in education, their children wont either. and so main think the main driver of how well children do in education is the teacher. its not. and they seem to think that private schools do better. not really its just that parents have a bigger stake in the education, after if you are paying 30,000 to 60,000 a year in tuition, you are more likely to be interested in how your child is doing. but some of the best schools are private, they are public. and they dont have as easy a time of it, as private school can and do pick their students

  8. jnkowens says:

    In fact, we thought “Idiocracy” was a satirical movie. It turns out, it’s a documentary.

  9. Robert M says:

    I think the article is a come on for the immigration debate and native intellgence, specifically the idea we do not move as much and eat the wrong food for ntelligence. I suggest you read this and the follow up ideas:

  10. 873450 says:

    “Is Modern Life Making Us Dumber?”

    Smartphones are making us zombies hazardous to ourselves and everyone around us.

    You see them everywhere walking on sidewalks and driving in traffic, looking down intensely with their concentration locked onto a handheld device, unaware of what’s directly in front of them, oblivious to surrounding pedestrians and traffic, weaving and zigzagging like a drunk, suddenly changing speed and direction, abruptly stopping… Conversations with 21st century zombies are frustrating. They are physically present, but mentally somewhere else. We’ve seen funny videos of walking zombies disappearing through open manholes, falling into fountains, tripping down stairs and escalators. We’ve seen tragic commercials ending with incomplete, inconsequential text messages composed by zombies killing themselves, their passengers, pedestrians and occupants of other vehicles zombies crash into. Penalties and enforcement need to be ratcheted up.

    Now smartphones are built into eyeglass frames. What’s next? Brain implants? How much more technological distraction do we need?

  11. victornl says:

    The argument of a correlation between poverty and high fertility is also only part of the story.
    Turns out that the very rich families or nations, have a higher fertility than medium rich families or nations:
    As the world is getting richer, the fertility correlation will be completely reversed, the poor will have the fewest offspring, the richest the most.

  12. Greg0658 says:

    interesting thread .. 1st thing that my brain said “can’t be” the fact we are slower at dexterity .. in a world of class act video gaming? must have tested the wrong bunch of kids

    2nd LOL @ “Idiocracy” the documentary

    3rd on IQ being bred in or installed by education & experience – thats way over my head – better stay out of it .. but it doesn’t much matter except to folks running the rat race

    4th – possible causes I wonder about & not mentioned (or breezed over)
    ~ electrical energy pounding to our minds & bodies
    ~ chemicals ingested into our minds & bodies – mostly (not totally) including hallucinogens & alcohol
    ~ now must admit the great Google for spelling (& leads to)
    ~ the final thought “just not as needed” things are never more fluffy for us humans (for now) data retention of information & processes – to pass on has never been better

    on that 3rd that I didn’t want to touch – family environment opportunity is important to growing minds – the carrot and stick approach or beatings and starvation are not going to work as well in the future (at least the near future) and with the wealth of information available nowdays – lets say the superstitions list a-z has been outgrown

  13. formerlawyer says:

    Just a datapoint. Could you pass the Victorian era entrance exam to Harvard?

  14. Research done to prove a hypothesis (as opposed to disprove one) is inherently suspect. Trotting out crotchety old Gerry Crabtree to support suspect conclusions is another flashing caution light. Comparing IQ measurements from 120 years to now in any quantitative fashion, without correcting for many confounding factors, is idiotic regardless of whether Darwin’s cousin was involved. Purifying selection is (still) acting strongly and with a high degree of specificity against mutations that cause deficits in intellectual function based on a number of recent publications. See, for instance:

    (Disclaimer: some of this is my own work.)

    It amazes that so many people who are happy to accept conclusions like this at face value are so strikingly (willfully?) ignorant of human history. Infectious disease was the main killer of human until about, oh, 70-80 years ago. Recent relaxation of that selective pressure has far more influence on anything going on now than smartphones and lack of exercise.

    Beware of science by press release.

  15. beaufou says:

    Neuroscience is used in branding as well as political propaganda, any surprises here?
    Not only are we getting dumber but we are also in danger of self destruction.

  16. Biffah Bacon says:

    IQ and g tests don’t measure what they purport to measure, full stop. They measure conformance to an arbitrary social norm and willingness of subjects to comply, put forth an honest effort, and persist in taking the tests to completion. They are constructed in order to winnow out non-conformists and out-culture or out-language test takers; let alone those actively resisting, bored or hostile to the enterprise.
    Contrast that to the college entry exams with their array of test prep classes and materials-it’s been demonstrated that people’s test scores improve over time as they acculturate. Flynn’s book is worth reading.

  17. constantnormal says:

    There are many answers to the Fermi Paradox, all of which can be glimpsed by careful observation of the one example we have of “intelligent” life …