IQ is supposed to measure intelligence, but does it? Head to https://brilliant.org/veritasium to start your free 30-day trial, and the first 200 people get 20% off an annual premium subscription.
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A huge thank you to Emeritus Professor Cecil R. Reynolds and Dr. Stuart J. Ritchie for their expertise and time.
Also a massive thank you to Prof. Steven Piantadosi and Prof. Alan S. Kaufman for helping us understand this complicated topic. As well as to Jay Zagrosky from Boston University's Questrom School of Business for providing data from his study.
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References:
Kaufman, A. S. (2009). IQ testing 101. Springer Publishing Company.
Reynolds, C. R., & Livingston, R. A. (2021). Mastering modern psychological testing. Springer International Publishing.
Ritchie, S. (2015). Intelligence: All that matters. John Murray.
Spearman, C. (1961). " General Intelligence" Objectively Determined and Measured. - https://ve42.co/Spearman1904
Binet, A., & Simon, T. (1907). Le développement de l'intelligence chez les enfants. L'Année psychologique, 14(1), 1-94.. - https://ve42.co/Binet1907
Intelligence Quotient, Wikipedia - https://ve42.co/IQWiki
Radiolab Presents: G. - https://ve42.co/RadioLabG
McDaniel, M. A. (2005). Big-brained people are smarter: A meta-analysis of the relationship between in vivo brain volume and intelligence. Intelligence, 33(4), 337-346. - https://ve42.co/McDaniel2005
Deary, I. J., Strand, S., Smith, P., & Fernandes, C. (2007). Intelligence and educational achievement. Intelligence, 35(1), 13-21. - https://ve42.co/Deary2007
Lozano-Blasco, R., Quílez-Robres, A., Usán, P., Salavera, C., & Casanovas-López, R. (2022). Types of Intelligence and Academic Performance: A Systematic Review and Meta-Analysis. Journal of Intelligence, 10(4), 123. - https://ve42.co/Blasco2022
Kuncel, N. R., & Hezlett, S. A. (2010). Fact and fiction in cognitive ability testing for admissions and hiring decisions. Current Directions in Psychological Science, 19(6), 339-345. - https://ve42.co/Kuncel2010
Laurence, J. H., & Ramsberger, P. F. (1991). Low-aptitude men in the military: Who profits, who pays?. Praeger Publishers. - https://ve42.co/Laurence1991
Gregory, H. (2015). McNamara's Folly: The Use of Low-IQ Troops in the Vietnam War; Plus the Induction of Unfit Men, Criminals, and Misfits. Infinity Publishing.
Gottfredson, L. S., & Deary, I. J. (2004). Intelligence predicts health and longevity, but why?. Current Directions in Psychological Science, 13(1), 1-4. - https://ve42.co/Gottfredson2004
Sanchez-Izquierdo, M., Fernandez-Ballesteros, R., Valeriano-Lorenzo, E. L., & Botella, J. (2023). Intelligence and life expectancy in late adulthood: A meta-analysis. Intelligence, 98, 101738. - https://ve42.co/Izquierdo2023
Zagorsky, J. L. (2007). Do you have to be smart to be rich? The impact of IQ on wealth, income and financial distress. Intelligence, 35(5), 489-501. - https://ve42.co/Zagorsky2007
Strenze, T. (2007). Intelligence and socioeconomic success: A meta-analytic review of longitudinal research. Intelligence, 35(5), 401-426. - https://ve42.co/Strenze2007
Deary, I. J., Pattie, A., & Starr, J. M. (2013). The stability of intelligence from age 11 to age 90 years: the Lothian birth cohort of 1921. Psychological science, 24(12), 2361-2368. - https://ve42.co/Deary2013
Flynn, J. R. (1987). Massive IQ gains in 14 nations: What IQ tests really measure. Psychological bulletin, 101(2), 171. - https://ve42.co/Flynn1987
Why our IQ levels are higher than our grandparents' | James Flynn, TED via YouTube - https://www.youtube.com/watch?v=9vpqilhW9uI
Duckworth, A. L., Quinn, P. D., Lynam, D. R., Loeber, R., & Stouthamer-Loeber, M. (2011). Role of test motivation in intelligence testing. Proceedings of the National Academy of Sciences, 108(19), 7716-7720. - https://ve42.co/Duckworth2011
Kulik, J. A., Bangert-Drowns, R. L., & Kulik, C. L. C. (1984). Effectiveness of coaching for aptitude tests. Psychological Bulletin, 95(2), 179. - https://ve42.co/Kulik1984
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Written by Derek Muller, Casper Mebius, & Petr Lebedev
Edited by Trenton Oliver
Filmed by Derek Muller, Han Evans, & Raquel Nuno
Animation by Fabio Albertelli & Ivy Tello
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Produced by Derek Muller, Casper Mebius, & Han Evans
Someone tell me his iq result the exact minutes he revealed it
@Strawberrihead Says:
16:48 I was holding my breath for the moment racisim was brought up LMAO. The more I learn about the G factor and Stanford University and the people it's produced, the more I'm convinced the institution is a eugenics factory.
@IntellectualAardvark Says:
I've only ever done one professional IQ test to diagnose potential dyslexia. I got 106.
I hate them and find them confusing and the questions mostly annoying and pointless. I think if you do lots of IQ tests your score will go up.
@SwampDonkey64 Says:
I have noticed with intelligent people they are less likely to take a risk if it seems 75% likely to fail. As to where someone not so intelligent ignores that 75% and pushes through. The not so intelligent person that persevered is among a very small percentage of success stories. 75% that weren’t successful were not people that just failed but people who saw the writing on the walls and got out early due to their ability to do so. Then we look around in the world and we say how in the heck did that guy do that, yet all I do is struggle to try to keep up with the Jones. Less willing to take a risk is less willing to fail. Sometimes we need to learn to just jump with our eyes closed. What’s the worst case scenario, we have to get up and brush ourselves off to begin again. Haven’t we been there plenty of times in the past? Maybe that’s what we use our intelligence for, is just being able to know how to get up and brush yourself off. But if you’re like me the more times you jump the fewer times you are willing to jump. You want a perfect example? BITCOIN.
@FuSiionCraft Says:
Real, scientific IQ tests are, contrary to popular beliefs, extremely reliable. They measure a vast pannel of different intelligence.
@billjones9056 Says:
There is absolutely no known way to improve i.q. Education certainly does not. 20:30
@Nick-f4w2n Says:
We went the opposite of eugenics and started heavily subsidizing the bottom tier of society. Now studies show declining IQ on a society wide level. lol
@Kommand_alt Says:
If taking IQ tests is your power, what are you without it?
@waltg5165 Says:
IQ is testing someone's ability to perform in modern society given the current environment. The person might be a genius when it comes to persistence hunting, but how useful is that in modern society?
There are a lot of dumb people in all races, we had short buses and special classes, we held students back grades, and what happened? The race of people scoring 70 on IQ tests in Africa score 70 here, and we are racist. The darker side of decreasing the gap, was taking away options that existed before trying to decrease the gap. People wanted to learn to read and write, parents didn't want illiterate kids, and now everybody is promoted because we don't want to hurt feelings.
You never took an IQ test? BS. 100%, if you went to school, you were tested. Good try, you aren't that dumb.
If you have a business model that needs someone to know the intricacies of persistence hunting, we would be set. Considering mastering that skill genius if disingenuous. You would not make these types of arguments if your Car insurance premium would change because of them.
We need people with useful skills now, if the tests do not measure that like in NY, we can't use them. This idea the system is a problem for not recognizing people with mediocre skills is a testament to the approach.
There is a rating system in chess, it does not translate to IQ, but it is relevant to the game of chess as it is played. IQ tests and standardized tests are doing the same thing in regards to what skills are needed to function in life. Knowing how the pieces move is the only way to start.
Call it what you want, but if you don't think that matters, you have missed the point.
@7117memo Says:
The high IQ can predict only the fact you will be bullied by every low IQ person who know you are above average just to prove he can.
@Sharpgod_1 Says:
i think focus, motivation, education level all play a factor in someone’s iq, i don’t think there’s a way to measure raw iq
@SomeoneElse-42 Says:
9:03 3,5,8,12... it can be 16 too. 3*2-2^0 = 5, 5*2-2^1 = 8, 8*2-2^2, 12*2-2^3 = 16
@SomeoneElse-42 Says:
3:36 If this is correlation then the diagonal should be 1.
@abru_Qor Says:
That professor sounds a little bit like a Pakled...
@patrickcourtney796 Says:
OK 3 minutes into this explanation I was lost IQ - 40
@Magiktcup Says:
Only did an IQ test once and came back exactly 100 though i was stoned
@afkarezky Says:
I also took an IQ test when I was in school, and my score was 121. From my own experience, one thing I noticed is that people with higher IQ scores often seem to pick up logical reasoning more easily.
When I compared myself with some friends who had lower scores, they often had more difficulty recognizing when something didn’t make logical sense, following a chain of reasoning, or understanding concepts that rely heavily on logic.
Programming was one of the clearest examples for me. People with stronger reasoning ability often seemed to understand programming logic, conditions, loops, and problem-solving patterns faster.
That doesn’t mean a higher IQ makes someone smarter in every way. Knowledge still comes from learning, experience, and effort. Someone with a high IQ can still know very little about a subject, while someone with a lower IQ can become highly knowledgeable through years of study and practice.
So for me, IQ seems to be more about how easily someone processes patterns and logical relationships, rather than how much they actually know.
@rainleistone9349 Says:
i tried to take an IQ test once, i got 25 or so questions in and got bored. That ADD diagnosis never felt so accurate 😅
@DrakeTerry-j8c Says:
19:10 this is very dark. I would like to point out that it is extremely similar to the argument in support of abortion (at least a large part of it) that it "would be better for this person not to exist because their quality of life would be unsatisfactory"
@Xirks4 Says:
IQ test just feel like a scam thing imo. I went from 124 with 6 to 86 with 16 back up to 105 with 21 so yeah
@pigscanfly2by2 Says:
Intelligence is genetic as we, whether we like it or not - are animals. Having parents that are within the region of being reasonably intelligent ie 105 and culturally predisposed to being involved in their children's lives naturally will have children who will have similar IQ's or better - the same situation applies to apes who teach their offspring. Having knowledge creates more knowledge. The more successful one is in gathering knowledge the healthier one is - thus the reason why intelligence is associated with longevity. I can see those same outcomes in my family tree where on average people die deep into their 90's getting to ages of 105 - all either in the teaching or engineering fields. I therefore think genetics plays a crucial role. We are Scots.
@kingromaniaDE Says:
What's wrong with who? 🧐
@Anonimowany1 Says:
I measure intelligence by the decisions people make in their life.
You can have low IQ test score, but if your decisions in life end up making yourself feel content and happy with your life and you feel overall comfortable - you are way smarter and more intelligent than the CEOs or wealthy people or sucessfull individuals who stress on a daily basis and don't really feel happy as a result.
You can be the most intelligent guy in the room, but if your decisions in life don't make your life happier and easier - you're dumb.
@rumlia Says:
Intelligence is what IQ Tests Test according to, especially, the USA.
@rumlia Says:
Ask a very high IQ to live in a habitat for 1 year without help in where millions have lived for 10s of thousand years.
A virgin forest in the Amazon, middle India....
@rumlia Says:
IQ questions proportional to what are taught in schools, communities, and homes. 😮
@rumlia Says:
8 Intelligences of Howard Gardener. 🤔🫢
@rumlia Says:
Correlation is not Causation. Russel Ackoff submitted a paper in the 1900s suggesting a strong correlation between tobacco smoking going up and reduction in cases of cholera. The paper was not accepted because it was considered "facetious"!
@rumlia Says:
Mismeasurement of Man, anybody?
🤔
@rumlia Says:
Is a correlation coefficient of .33 HIGH? High IQ : Brain size.
Disclosure my IQ is about 70, or so I think. AND English is not my native tongue.
🤔
@00BeesKnees00 Says:
All of this is pointless. Humans can't beat AI.
@floydnine5025 Says:
My grades reflected one thing - the interest I had in the subject, or natural ability (I was good at writing, but struggled with complex math). It was either easy, or hard. Also if it took place outside the classroom, it was not a priority. I quit doing homework by high school, and passed with 60-70% averages simply due to multiple choice. I mean there was vagina everywhere for the walking boner, and schoolwork was uncool and busywork! Bah! A D- diploma is still a diploma!
@Draakie100 Says:
What is the ultimate goal in life ? It is being happy in life. Now take the IQ test and look at how much it has to do with being happy in life. Great channel, thanks for all the interesting uploads. Very best wishes to all 🎉❤
@tylerclarkson299 Says:
Societal IQ peaked with the millennial generation. We’re now purposely trending backwards thanks to the very groups that started eugenics.
@IvIv-j6x Says:
I scored 115 when i was a teen, kind of a hit to my ego back there, now i dont care cause i know how it works
@bearbryant3495 Says:
When I was a CO an inmate asked me if I knew anything about MENSA. He said a guy at the college wanted him to take the test.
@DaisyPeach-q8v Says:
20:50 Knowledge is not intelligence. The ability to use knowledge is part of intelligence. Naming knowledge Crystallized Intelligence doesn't make it intelligence. This is why "Crystallized Intelligence" remains steady over time; because it's just something you memorized lol.
@TravisBowen-q3y Says:
Due to 40 years of rethuglicans defunding education the IQ of the average American is 75.
@mynameisjoyinsanskrit Says:
like pay somone like based on iq when tooken maybe it will boost even more
@mynameisjoyinsanskrit Says:
g is changable here though even though it has genetic it has correlation but gentral intelligence has like more study can also increase iq too though
@jackwhitestripe7342 Says:
I have 120 but .... you understand
@karaimbopi9672 Says:
nice video, exelent story telling on what the history of this test is, learnt something new today, thank you <3 subscribed
@Somewhere-In-AZ Says:
I’m smart enough to know I’m not.
@veezeeks Says:
"top three earners had an IQ below 100" found the ceos
@frankhodge7654 Says:
When IQ tests are used to place young students into select programs of education, their use makes sense even though the tests are biased based on economic and ethnic factors. The students are shown to be doing better or worse than their peers based on their mental age. However, when an ADULT takes an IQ test, how can you compare the "mental age" of a 28-year-old scientist with high verified intellectual performance in laboratories with a 56-year-old law clerk who gets high respect in his daily work performances. Is the 56-year-old expected to do twice as "well" in mental tasks as that 28-year scientist or vice versa? Of course not, that idea seems silly to everyone. For adults such a quotient cannot be created.
I have always done very well on such tests because of my good memory and high test-taking skills, and I have retired in a comfortable economic situation. Nonetheless, I agree with Stephen Hawking that these tests measure a lot more life aspects (economic status, personal curiosity, psychological factors (depression/confidence, positive and negative views of humanity, outlook about the future and types of cultural views), and personal education and experiences.
ONE thing that adult IQ tests do tell us is how curious and open to different ideas the test-takers are. The higher the score, the more likely those factors will be present, the lower the score, the less likely those factors will apply. However, even in those tendencies the scores do not ALWAYS tell an observer the correct tendency of that individual.
@isaacrobinson7608 Says:
you can ruin an IQ test by studying for it, because if you improve your skill on the specific questions. you prepared for them, to have the high IQ, you should be able to go in there raw without seeing any of it
@youbli Says:
09:23: 60 isn't "four times bigger" than 15. It's _three_ times bigger.
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