The decline of Human Intelligence: Why Are People Stupid?


This was inspired by some of the questions here. This isn't to hurt anyone, just wanted to look into this. Most people on this website are probably decently smart, but you can be the judge of that. IMPORTANT: Added the Bold to help, this is a long MyTake so I hope that makes it easier to read in bites.

The decline of Human Intelligence: Why Are People Stupid?

Humanity has experienced high levels of intelligence and numerous technological advances since the 18th century, however IQs are in the decline and falling rapidly. In a study first published by National Academy of Sciences showed that IQ scores has fallen every year by 0.3 points since the mid-1970s. Western countries has lost a total of 15 IQ points since the peak in the 19th century, which is as significant difference.

Things genetically correlated with higher intelligence has dwindled, from your reaction speed and the complexity of your vocabulary. Your academic success in school and socioeconomic status ate also related to your intelligence.

In countries like Iceland, the genetic disposition of educational attainment is being selected out of the population. In a research article published on PNAS noted "A recent study of ∼20,000 genotyped Americans born between 1931 and 1953 provided direct evidence that the genetic propensity for educational attainment is associated with reduced fertility-". People who are highly educated have fewer children and fewer generations.

The decline of Human Intelligence: Why Are People Stupid?

The effect is more pronounced for women as those of higher socioeconomic status usually use birth control more effectively and limit their fertility. Women of higher IQs also tend to seek abortions on time when faced with an unwanted pregnancy (check the last source on the list).

yet, what is intelligence? How is it measured? There are different kinds of intelligence, like your abilities and skills. How well you do socially and communicate is correlated with intelligence (0.3 correlation, 1.0 is the highest, 0.1 means basically not correlated). What is underpinning the different types of intelligence and your overall cognitive ability is the G-factor, otherwise known as general intelligence. General Intelligence is highly genetic at 0.8 heritability with a few rare outliers. it is difficult to measure, IQ tests can only indirectly measure it. Concisely, Intelligence can be defined as "the ability to solve cognitive problems and to solve them quickly."

There isn't currently any based way to change your IQ although you can improve at doing tests. The average IQ score in developed countries is more or less 100, this would include careers like data entry, becoming a Clerk, Cashier, or Police Patrol Officer. Someone around an IQ score of 87-93 would likely work as a Janitor, Factory worker, or packager. "What IQ predicts to some degree is how rapidly you can learn something but once you've learned it, it doesn't necessarily predict how well you do at it. People with lower IQs are more suitable to more repetitive jobs."

The decline of Human Intelligence: Why Are People Stupid?

On the other hand, a portion of the population has an IQ of 85 or lower. The exact number varies. The average IQ in the US is 98 so it's likely that 19% of Americans have an IQ of 85 or less. Jobs for people with an IQ of 85 or less are limited, even the military bans people with an IQ of less than 83 from enlisting. People with an IQ lower than 95 can experience difficulty finding work. Those chronically on welfare (In the US) have an average IQ of 90, according to an article published on PBS. Criminals often have an IQ lower than 95.

However, a person with a below-average intelligence can still live a decent life if they do choose to, personality also plays a big role in this. One of the things that Richard Haier mentioned was that although most people would choose to be smarter, intelligence doesn't determine your character exactly.

Why is Intelligence decreasing though? This is the question I wanted to answer with this post, hopefully with an understanding of it matters. Prior to the industrial revolution, Intelligence was being selected for, among other traits. Things like height, brain size, and facial symmetry are correlated to some degree with intelligence. Less intelligent people have more children and more generations. People with an average IQ or higher tend to have less than 2 children and have them later in life. Countries with a welfare state also help families of lower IQ to pass their genes on as previously mentioned. This as well as a lower child mortality rates means that natural selection weaken; traits that would have been selected against remain. The more intelligent a person is, the more likely they are to adopt to the current society and ideology. Religiosity is associated with having more children but the more intelligent a society is the less Religious it becomes. This is a factor that has affect many developed countries in Europe and North America as society has moved towards a more leftist, atheist norm.

Note: I might write about how does a Low IQ society and how the transition to one looks like. Developed countries appear to be in the middle of a transition. Demographics is a topic I've found interesting for a while now. I hope this works as an introduction of sorts for the both of us.


I've been looking into this topic for a while but this is a few articles and videos that I used specifically for this MyTake, feel free to take a look:

  • Why are our IQs Falling? (Video by TDLR News Global)
  • Lecture by Edward Dutton at ASBIRO University on the decline of intelligence
  • (Video by Hydrostatus Systems)
  • Richard Haier: IQ Tests, Human Intelligence, and Group Differences | Lex Fridman Podcast #302 (Video by Lex Fridman )
  • IQ Test Scores Are Getting Higher, But Are Humans Actually Getting Smarter? (Article by Sciencealert)
  • Genetic and environmental influences on reaction times: Evidence from behavior-genetic research (Study published on research gate)
  • Selection against variants in the genome associated with educational attainment (Article on , first on PNAS)
  • How much is academic achievement shaped by genes? (Article published on the BBC)
  • The high heritability of educational achievement reflects many genetically influenced traits, not just intelligence (Article published on PNAs)
  • Jordan Peterson - What Kind Of Job Fits Your IQ (There's an animated clip posted by The Wisdom Wire on Youtube)
  • Research Confirms a Link between Intelligence and Life Expectancy (An article published on the Scientific American).
  • Analysis: How poverty can drive down intelligence (Article published on PBS)
The decline of Human Intelligence: Why Are People Stupid?
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  • Mcelroi

    Interesting it’s since the 70’s when the cia began its global domination campaign. I would say that intelligence is discouraged for most people because they are much easier to control. Intelligent people will call you out for malfeasance - but only if they are in numbers. With less intelligent people to be voicing opinions, the overarching opinion drops in intelligence too.

    But aside from the very obvious cia strategies that benefit them only, there’s another factor: genetics. When we need smart people - like leading up to the world wars, we produce them in abundance. When we don’t though, our predisposition is to have a ton of followers who keep their heads down and their mouths shut, leaving the decisions to whoever is smart enough to get in charge.

    And that’s why we see such a great divide between the 1% - they’re smarter, they’re calling the shots, and the rest of us are left behind wondering how they did it. They make it seem like it’s a lottery, but the truth is, your chances of “winning” go up exponentially the more intelligent you are. Since intelligent people either 1) know that having tons of babies is unethical and irresponsible, or 2) don’t want a bunch of babies getting in the way of their power conquests, it makes sense that they’d eventually filter the unintelligent to the bottom, leaving the most intelligent leading us.

    Even George bush was a Yale grad, and not just because of daddy’s influence. He is actually smart. He’s dumb in many ways, but some of those are part of his image he wants to portray. You’ve gotta be pretty smart to convince everyone you’re an idiot when you really aren’t.

    I mean, he did beat the game - he made it to president. That’s something no short busser could ever hope to achieve. Same with trump - he’s transparently a business genius - he knows how to manipulate the people around him to get what he wants.

    That said, expect a further divide to grow - this is all human nature.

    LikeDisagree 2 People
    Is this still revelant?
    • First, assuming the less intelligent and less fit are reproducing at a higher rate and thereby lowering the average intelligence, that does not lower the average IQ of those with higher intelligence because normally they mate with each other.

      I have mixed emotion regarding child support. If married, if there is no provable agreement then child support should be whatever the law is. Otherwise, it should be whatever the parties agree to and the courts should only enforce their agreements, if necessary. If the parties are not married the court should enforce whatever written agreement, if any. However, most likely there would be no written agreement between unmarried parties unless they were living together. If they are living together, treat them like they are married.

      However, I believe in almost all cases, there would be no written agreement as most would be one night stands or short term affairs. In those cases, I believe child support, if any, should be limited to what the state would pay to support a child when they can't find the father. However, if it can be proven that no child support will greatly reduce out of marriage children, I am inclined to believe there should be no child support. Young women can protect themselves by not getting pregnant and likely will, unless they have a written agreement, if they don't see it as way to get money.

  • globetrotter22

    “This is a factor that has affect many developed countries in Europe and North America as society has moved towards a more leftist, atheist norm.”

    Do you really believe that the “leftist, atheist norm” is the ultimate sign of a more intellectually advanced country?

    Is this still revelant?
    • Yes it is.

    • @Danzigdawson or more accurately sure it’s possible for a leftist, atheist country to be “intellectually advanced”. But that doesn’t mean intellectually EFFECTIVE. That is the standard living, general welfare, life expectancy and personal freedom exemplary in countries that are following “leftist, atheist norms”?

      Before you yell “Sweden” need I remind that all communist countries such as Cuba, North Korea, China and Russia (no longer communism but society was indefinitely impacted that society) follow the “leftist, atheist norm”.

      Also just because you have a high IQ doesn’t always mean you are productive person let alone an effective one. Sometimes your IQ enables you enact wide scale self destructive behavior towards yourself and others.

    • Religion is negatively correlated with intelligence and positively correlated with stress levels so you're not wrong, @globetrotter22. It is a sign of a more intelligent society, it doesn't exactly mean everyone is smarter if they're leftist. Intelligence used to mean higher survival rate because you knew how to (and religion was more of a survival guide). now, in developed countries, more people survive and with more time in their hands to question religion.

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Most Helpful Girls

  • Amy10223

    This is an interesting topic, but it seems you cut and paste some things. Also, some writing doesn’t make sense… when you wrote this,

    “This is the question I wanted to answer with this post, hopefully with an understanding of it matters. Prior to the industrial revolution, Intelligence was being selected for, among other traits. Things like height, brain size, and facial symmetry are correlated to some degree with intelligence. Less intelligent people have more children and more generations. “

    …the first two sentences don’t make sense or are incomplete in thought.
    When you wrote this…

    ”. There isn't currently any based way to change your IQ although you can improve at doing tests. The average IQ score in developed countries is more or less 100, this would include careers like data entry, becoming a Clerk, Cashier, or Police Patrol Officer. Someone”

    You start off by talking about how IQ cannot be changed, then you begin talking about what different jobs you can have with differing IQs. The writing doesn’t stick to the topic in each paragraph.
    So if you are writing this for a school paper, I suggest going over some details to make sure you stick with the ideas you’re talking about and you don’t go off on tangents. I’m just curious as to why you’re writing this here, as well.

    Is this still revelant?
  • KelleyNice

    Your conclusion are flawed because your last reference states "that intelligence as measured by IQ tests has actually increased over the past 50 years."

    In any event, assuming the average IQ is decreasing, child support laws and family courts are a major reason. That is because, for all except the last few decades of human history, women would mate with a good provider but when ovulation would have sex with superior males thereby unconsciously attempting to select the best genes for their eggs. However, due to child support superior men are refusing to have sex with less intelligent and lower class women.

    Is this still revelant?
    • @KelleyNice you are correct, IQ has technically increased recently. that seems to be due to the Flynn effect (people maximizing their general intelligence by being heathier or getting educated). This is a pretty decent article about it but I can find you studies if you want. The Flynn effect has been in reversal since the 1980s-1990s, particular among more developed countries like Norway or Denmark. The flynn effect though is related to the 20th century, after IQ tests were invented and we didn't rely on reaction times or other markers of intelligence to estimate IQ so that's might be another reason why IQs rose.
      Although, what do you think, if anything, should be done with child support laws? Is it a good or bad thing in the case of intelligence?

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What Girls & Guys Said

  • Guy__

    For one, we've never had this much fluoride in our environment. And the officials are saying "there is evidence that fluoride does (list of 100 scary side effects) but authorities around the world decided that we should only increase the amount of fluoride we pump into you".

    And fluoride is shown in many studies to lower IQ

    Considering IQ, I disagree that when there is a correlation, higher IQ group is always right. For example Hitler had above average IQ, 140s or something, and 99% of us will agree that he wasn't a good person. Obviously IQ is important, but not the full story. We need more than just focusing on the number. And the School systems were designed to dumb us down. Why else would exist...

    Like 1 Person
  • MCheetah

    I saw this post a few days ago. I didn't respond to it until now, because I was unsure if could add anything worth saying. Usually on GAG, if there's nothing of value I can add to the discussion, I won't say anything.

    I guess the first thing would be to argue if IQ is really accurate or not. To me (with a supposed 150 IQ, even though everyone on GAG sees me as a complete retard), I've always thought of IQ as a quick quantifier of one's potential intelligence in critical thinking, in relation to another. For example, I could say "I'm at least 50% smarter than you." Of course, that's if you don't take the other forms of intelligence into account, assuming you believe those to be equally or more valid as IQ.

    The decline of Human Intelligence: Why Are People Stupid?

    As another example, Mike Tyson supposedly once said, "Social media made you all way too comfortable with disrespecting people and not getting punched in the face for it." Which is ironically, the smartest thing he's probably ever said, if true. Someone may be a math genius, but also too stupid to not know when to close their mouth in public and think they won't catch four knuckles to the mouth. When a math genius is lying half-conscious on the ground, with a bloody lip, he doesn't exactly look all too smart then, does he? Being a social retard is real and exists daily on Twitter. So no, logic intelligence and critical thinking isn't everything. Even I knew that being unpopular in high school.

    The decline of Human Intelligence: Why Are People Stupid?

    Secondly, I think there seems to be a mix-up with knowledge and intelligence. While I can agree both are sinking in modern society, data and studies usually just focus on knowledge, and knowledge is NOT intelligence. There's an old saying I'm about to screw up, but it goes something like "Even an illiterate hillbilly can play Country Road on the banjo." Something like that. Knowledge changes and evolves based on the society we live in. While generations having less knowledge each year, may seem scary at first, you have to realize that we still have all that knowledge at out fingertips with smartphones and the internet. Now who CONTROLS that knowledge and keeps it pure from bias and politics, is a story for another day. But children have less brain-knowledge because Google exists at their fingertips.

    I'm old, but not that old. And when I was young, we all had to remember each other's phone numbers. As well as addresses, schedules for TV shows, birthdays, etc. Just because a smartphone has made it so that remembering phone numbers is no longer a thing, doesn't make people less intelligent overall, even if it makes them less knowledgeable, to a degree. How many students still know the periodic table? Or US state capitals? My point is, less knowledge isn't necessarily bad, as long as the knowledge is still accessible somehow. (The separate problem being, who controls and upholds the knowledge.")

    The decline of Human Intelligence: Why Are People Stupid?

    Also, growing up, I was always thought intelligence meant something else. That "intelligence is the ability to understand the complex world around you and explain it to others." As in, you have to also be able to TEACH what you know, as well. While intelligence can't be "taught," knowledge and understanding can. "General Intelligence" could be considered "common sense." And common sense, despite its name, is only common based on the environment you're in.

    Thus ironically, only "common" to those in that environment, and not to anyone else. What you call "general intelligence" is similar, but with a little more knowledge added to it. As in, common sense is to not raise your middle finger to people unless you want to offend them. General intelligence is knowing water freezes at 32 F and 0 C. Or that the Earth revolves around the sun every 365(ish) days. BOTH of these, are actually forms of knowledge, not "intelligence."

    So if society lacks them, then that is a teacher/knowledge problem, not an "intelligence" problem.

    Lastly, one more thing I will bring up: "The more intelligent a person is, the more likely they are to adopt to the current society and ideology." Except for one problem in that flaw: That only works if they desire to do so, or see no problems with the "current society." Current Western society tells children they should take hormone blockers, be a feminist, and learn about LGBT sex in the first grade. Yeah... I'm not adapting to that society.

    But WHY is society like this? Well, that has nothing to do with intelligence at all: It has everything to do with power and control. I'm running out of typing space here, but the short answer to your general question: "Why are we living in such a Low IQ society?" That's because it's harder to control a population of free-thinking intelligent individuals than it is to control a population of idiotic woke sheep on TikTok. Yes, it is all intentional. And yes, it does seem to be working for those with ill content, doesn't it?

    The decline of Human Intelligence: Why Are People Stupid?
  • Telekinetic-Potato

    Very interesting. Only in the case of a populated area like mine, I've noticed the rich people tend to be a little dumb sometimes. There's a subset of the population that is primarily supported by having their rich friends or family take care of them from a very young age.

    Our brains are interesting in that when we're young and developing, the brain is almost like a blank canvas, or like a circuit that hasn't been fully built yet. And our experiences and lifestyles shape our minds greatly.

    For example, my step brother's mom, she is an attorney for the state, pretty smart, fairly accomplished. Neither of her sons can tie their own shoes, use a toaster, use deductive reasoning or generally be considered smart.

    I know these two kids definitely could have been smart because there are certain tasks which they have been doing since a younger age they are very good at, but they don't seem to have the ability to learn, understand and internalize new ideas. Meaning the nuroplasticity of their brains has become compromised, or behaves like a much older person.

    What I'm trying to say is I think a lot of these "markers" for intelligence were decided before the concept of nural networks were fully accepted as an explication for how the brain worked. Meaning it's correlation, not causation and therefore is subject to many other factors which will change over time.

    A poor person at one place and time might be more likely to be stupid than a rich person or the other way around.

    I think intelligence is decreasing because it's becoming less necessary and schools are too focused on education and not focused enough on enriching ones mind.

    Schools in America for example all need to follow basically the same curriculum. It becomes cookie cutter and the original purpose is lost.

    And who needs to be smart when you don't even need to read a map and figure out where you are when a phone can just show you in terms even a total moron could understand (and people still get lost because, who cares, I'm in a gas powered car)

    So I think it's less that genitic stupidity is on the rise and more that we aren't developing our minds anymore as a society.

  • RavVid

    I'd like to say that it is the crap educational system that is the problem but can't.

    A strong indicator that IQ is more innate is that reaction speed is highly correlated with general intelligence. Reaction speed to me seems more something you are born with and innate.

    Nonetheless i rebel against the concept that education doesn't help you. It can certainly make you more capable even if not smarter.

    Look forward to seeing more on this.

    Like 1 Person
  • Daniela1982

    I don't know if you are joking when your question asks "why people stupid?" instead of "Why ARE people stupid?"

    The decline of Human Intelligence: Why Are People Stupid?
    Like 2 People
    • CalmMind

      This got me too. Even large news networks can't even be bothered to spell correctly anymore.

  • LovingLoverReturned

    Funny... I'm both religious and my first choice would be not to have children in this declining and diseased world... I view it as an unnecessary risk... I'd settle at 1-2 kids though. It's kind of morally wrong to want children for the purpose of making you happy... burdening the children... but for other good reasons, why not? I have not found any realistic intelligence tests, have you? They seem to focus on 1 of 9 types for intelligence only ( maths)

  • RiseofArtemis

    Natural selection lets the most intelligent live but due to our modern tech idiots survive who should have died. In other words we are causing our own rise in stupidity and not otherwise. IQ has nothing to do with how intelligent you are as there are different ways someone can be intelligent.

  • exitseven

    yes, having government reward welfare recipients by giving them bigger checks the more illegitimate kids they have is reverse Darwinism. The people who should not be allowed to reproduce are popping out 5 or 6 kids to get a bigger welfare check. No wonder IQ scores are plummeting.

    I think cell phones and cable TV are also to blame.

    Like 1 Person
    • And your Republican Party folks just made it more difficult for the poor and undereducated, and uneducated, to stop popping out kids. Be sure and thank them in the name of whatever they think they're doing.

    • exitseven

      @loveslongnails Ono of our former governors who was a Republican used to say that if you start giving out dollar bills you will have people lined up around the block waiting to get one. He wanted to limit welfare to 5 years and provide training for people on welfare. Once welfare queens saw that they stopped having so many kids. The plan was working until the guy decided to run for senate and a democrat was elected and reversed the program. Now welfare it through the roof.

    • I have a little news for you, numbers wise. Welfare recipients are primarily poor white, non-hispanics. Most people assume they are primarily blacks, but that's not true. Most welfare recipients receive benefits less than two years, including 2/3's who are gone in one year. Welfare recipients make up 4% of the US population. $131 billion is spent on welfare annually, which sounds like a lot but it's a fraction of the total US spending budget of 9.3 trillion dollars - 1.4%. However, ALL other programs for the poor, including Medicaid, represent another 14% of the budget.

      That's your biggest number - working poor who can't afford health care and are on medicaid. A welfare mom quickly hits diminishing returns after a 2nd kid, so it's a myth that more kids bring in more money than they cost to have. Getting off welfare and being able to afford health care, child care and everything else is a task for the uneducated, so this is no easy problem. It's not as simple as "get a job", or two, or three, because that's what it takes today to keep up. I don't know what the solution is, but I know what it ISN'T... and it ISN'T forcing the poor to have more babies while you scold them for getting pregnant in the first place.

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  • JDavid25

    That's kinda funny that Religiousness is related to lower IQ because right now Western society is more atheist and less religious than it's ever been.. Also, I listen to Prof Edward Dutton on YouTube, so I can definitely see some of him in this take.

  • monorprise

    "Intelligence" or rather the ability to learn isn't necessarily an evolutionary advantageous trait, this may be why it took the ecological disaster of the current Quaternary Ice Age to allow it to prosper for the first time.

    It may also explain the fermi paradox in the absence of evidence of intelligent life in the Galaxy inhabitable for 10 billion years.

  • Gent207-2

    I didn't bother reading your textbook explanation for your oversimplified title.

    You must be new here, idiots have been walking the Earth since the jump. There is nothing new under the sun.

  • Snsl153

    "Western countries has lost a total of 15 IQ points since the peak in the 19th century, which is as significant difference."

    This claim is clearly false, because the IQ test wasn't even developed until the early 20th century.

  • andreasderjuengere

    There is no ''human right'' to be smart.

    In fact, we need MORE 'stupid people' to get the work done that's -emm - unfavoured.

    Decline: A ''participation-trophy-culture'' that also worships ''freedoms'' for just any loser is as much to blame, as a greedy attitude of monetizing each and everything in the quickest way possible.

    (Guess, which ''culture'' matches here closest :) )

    Fun fact: the least smart people usually claim loudest to ''know stuff''.

  • Mickbert

    With the rapid expansion of technology people don’t need to “think” nearly as critically as we once did. Entertainment has become a massive part of our lives where in the past people didn’t have TV or video games so they did other things, board games, puzzles, reading, etc. which all pushed their critical thinking skills. Now we have smart phones and streaming content that does all the work for us.

  • TheSpaceGnome

    1. Most people of every generation were relatively dumb, but the number of highly intelligent people who participate in tests and statistical analysis, or go to college, is indeed less than it has been in prior generations.
    2. Stupid parents can often have genius children, and genius parents can often have stupid children, idiocracy was wrong.
    3. IQ tests are poor at measuring comprehension skills or creative thinking.

  • Adronicus

    The decline of human intelligence coincides with natural selection. I also believe there's a master class that works behind the scenes. Do smart people sound desirable if you're attempting to creat a slave class? Rather obvious the will of the few to dominate is greater than the masses collective will to remain free. Psychological prisons exist & they have a purpose..

  • Static_In_The_Attic

    I guess we can kind of thank evolution on this one & some people are proof evolution is moving in reverse. Nowadays some people are as sharp as a tac & some people are as sharp as a marble.

  • Friendlybro79

    I genuinely appreciate all the sources you stated that back up the thought you have. I wonder how much technology plays a role in the decline of IQs. I would love to know if technology has made things so much easier that we don't have to use as much critical thinking. An example I noticed even in myself is the use of GPS. I used to have better sense of direction 20 years ago lol. I'm so reliant on it now that it makes me think. Am I dumber because of this? Lol

  • Sixgunsound

    You should take a look at Wells’ The Time Machine for some insight into a Victorian English perspective of the devolution of human intelligence over time.

  • driven159

    Our brain is like a muscle you don't use it then it gets weak. Look at all the things that do the thinking for use when you want to know something your cellphone tells you we use to remember all our phone # addresses dates now your phone tells you how many of you have looked up stuff in a book most people can't fix anything like we had to before internet we all are dumbing ourselves

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