This blog is moving to

I created 2 blogs: for horror and for IQ, but it’s really not possible to run more than one blog successfully if you also want to have a career and a life, so despite all the great momentum that I’ve been lucky enough to have here, thanks to all of you (on Friday I had my greatest number of readers in history), I think in the long-run, it makes more sense to continue blogging at because that blog is far easier to find than

Also, Halloween is only a month away and that blog has a darker vibe…

My latest post is on the intelligence of Indian Americans.

Estimating the IQ of billionaires & the homeless from ethnic demographics


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According to an article in the New York Times, Jewish Americans have higher IQ’s than other Americans. There’s an old saying “if you’re so smart, why aren’t you rich?” so we should expect great wealth to be especially common among Ashkenazi Americans, given their IQ’s. Despite being 2% of the U.S. population, Jewish Americans are an astonishing 35% of the 400 richest Americans. This implies that U.S. billionaires are 1.67 standard deviations more Jewish than the general U.S. population. Assuming this Jewish over-representation was caused by the high level of Jewish intelligence, we can estimate the average billionaire IQ to be 2.9 SD above the U.S. mean or roughly IQ 143 (to understand the math, see here).

I would expect billionaires (at least the generation that made the wealth) to be extremely smart given that from a Darwinian perspective, intelligence is the mental ability to adapt any situation to your advantage. In addition, the rise of computer geeks, many of whom are billionaires and probably have IQ’s pushing 170 (a couple Microsoft billionaires reportedly scored perfect on the old SAT (IQ 171), though such claims tend to get exaggerated), is another reason to expect billionaires to be super-smart.

On the other hand, 143 is incredibly high given that IQ only explains about 16% of the variation in income (other factors like luck, hard work, ambition, good looks, charisma, special talents, connections etc, also matter a lot). For example Sara Blakely claims she flunked the LSAT, yet became the youngest self-made female billionaire largely because Oprah loved the footless pantyhose she created. Blakely is hardly an outlier. Dr. Bill Cosby was never a billionaire, but he was one of 400 richest Americans back in the early 1990s, and he claims to have scored 500 on the old SAT (IQ 85). Cosby’s obviously way smarter than IQ 85, and probably smarter than IQ 115 (in my humble opinion, the SAT is biased against kids from lower socio-economic background) but a good scientist can not throw out data arbitrarily:

If we assume that IQ’s on the Forbes 400 range from 85 (Cosby) to 170 (Microsoft), we might estimate that the average IQ would be about 130, a lot lower than what we’d expect from the extreme levels of Jewish over-representation.

As the hyper-educated blog commentator Pincher Martin noted, focusing on only Jewish representation can be misleading when trying to estimate the IQ of high achievers. It’s much wiser to look at other ethnic groups too.

Big Brained Oprah is still America’s only black billionaire

HBD has a sleazy reputation because back in the 19th century, HBD people were very mean to blacks and women, saying they were poor and powerless because they had small brains. We now know there are incredibly brilliant and big brained people in all large races and genders, and I find it absolutely fascinating that the only African American on Forbes list of the 400 richest Americans is arguably the biggest brained member of both her race and her gender.

From an evolutionary perspective this makes perfect sense, because brain size tripled in 4 million years of human evolution because only our biggest brained ancestors were typically adaptable enough to acquire enough resources to survive. Today, we have a social-safety net, so even small brained people survive, but the big brained Oprah has acquired orders of magnitude more resources (wealth) than most most Americans. It’s almost like you need some kind of rare biological advantage to become a billionaire. According to this New York Times article, Ashkenazi Jews might have IQ enhancing genes associated with certain diseases, and according to pumpkinperson, Oprah has a stratospheric brain size helping her to compete with the greatest Ashkenazi entrepeneurs.

Back in 1993, when you only needed about $330 million to make the Forbes 400 list of richest American, Bill Cosby was the only African-American to qualify, but big-brained Oprah was making money at record speed, and Cosby advised his young friend to always sign her own cheques. She took this advice, and the next year, with a net-worth of $340 million, she had dethroned him as the only African American on the list. Today, you need over a billion to make Forbes 400, and with a net-worth of nearly $3 billion, Oprah remains the only African American on the Forbes 400 (though the 2014 list hasn’t been released yet, but should be published any day now).

Estimating the IQ of the Forbes 400 from African-American under-representation

If African Americans are 12% of America, but 0.25% of the Forbes 400, then that means that the Forbes 400 is 1.6 SD less black than America as a whole. Does that mean that the Forbes 400 is 1.6 SD more intelligent than America as a whole? Of course not, because the correlation between IQ and sub-Saharan ancestry is small, and Oprah is probably a lot smarter than the average billionaire because she has far greater brain size and cultural influence and overcame adversity and very humble origins to achieve her wealth in such a competitive and improvisational field.

If there were a perfect negative correlation between IQ and African ancestry within the U.S., then the 12% Americans who are black would all be in bottom 12% of American IQ (below 83) and thus have an average IQ around the 6 %ile (IQ 77). But in reality, the average African-American has an IQ of 87 (perhaps higher in the younger generation raised in the post-civil rights era), so they score only 13 points lower than the U.S. mean of 100 on average (though some blacks score in the stratosphere), not 23 points lower. This implies that if it were possible to measure race on a continuous scale, African ancestry would correlate -0.57 with IQ (13/23). But since IQ only correlates 0.85 with general intelligence, and socially classified race probably only correlates 0.9 with actual ancestry, we need to divide 0.57 by 0.85 and then 0.9 to see that African ancestry has a true g loading of -0.75. Thus, the fact that U.S. billionaires are 1.6 SD less African-American than the U.S. as whole, suggests their average level of g is 2.13 SD higher than the U.S. average. But since even good IQ tests typically have only a 0.85 g loading, we multiply by 0.85, suggesting a mean IQ of 1.81 above the U.S. mean (IQ 127).

Two conflicting estimates

Based on Ashkenazi over-representation I estimate the Forbes 400 to have a mean IQ of 143 but based on African American under-representation, I estimate it to be 127. Let’s split the difference and assume the average self-made billionaire has an IQ around 135. Of course my analysis involved all members of the Forbes 400, not self-made members only, but since the children and spouses who inherit billions are virtually always the same ethnicity as those who made it, the ethnic distribution of the former just reflects the ethnic distribution of the latter several decades ago, even though trust-fund babies cognitively regress precipitously to the mean. Note that an IQ of 135 is similar to the IQ of 130 I estimated above for the Forbes 400, based on the SAT scores of Cosby and Microsoft billionaires.

Based on the 0.4 correlation between IQ and income, you’d expect people who are on average +5 SD in income to be (5 SD)(0.4) = +2 SD in IQ (IQ 130). It’s also worth noting that U.S. presidents (who live the life-style of a billionaire, despite earning only six figures in office) seem to have an average IQ around 130.

Estimating the IQ of the homeless

Although African-Americans are 12% of the U.S. population, they are 38% of the homeless. This implies the homeless population is 0.93 SD more African American than America as a whole. Dividing this figure by -0.75 and multiplying by 0.85 (see above) suggests the homeless has a mean IQ that is -1.054 SD below the U.S. average (roughly IQ 84).

Indeed, a study in the Canadian Journal of Behavioral Science stated:

In the complete sample of homeless individuals, a full-scale IQ score of 84.3 was reported. This is significantly lower than is estimated for the normal population. Indeed, 19.2% of the sample scored in the “extremely low” range, having IQ scores less than 70. Our findings are consistent with previous reports of IQ in homeless samples, which ranged from the “low average” (Seidman et al.,1997) to “average” range (Louks & Smith, 1988). Using the same IQ test as used in our study (WASI), Solliday-McRoy and colleagues (2004) studied a sample of homeless shelter residents in the United States and found a mean full-scale IQ of 83.7, with 20% scoring in the “extremely low” range. This finding is very similar to that found in our U.K. sample.

An average IQ of 84 for the homeless is consistent with pumpkinperson’s law: Average IQ varies 8 points with every ten-fold increase or decrease in financial success:

Three figure income earners (the homeless): Average IQ 84

Four figure income earners (part-time minimum wage): Average IQ 92

Five figure income earners (middle class): Average IQ 100

Six figure income earners (future millionaires): Average IQ 108

Self-made deca-millionaires: Average IQ 116

Self-made centi-millionaires: Average IQ 124

Self-made billionaires: Average IQ 132

Self-made deca-billionaires: Average IQ 140

If you made your money in STEM, add 10 IQ points to the expected IQ of your income. If you made your money in a low-brow occupation like selling pantyhose, perhaps subtract 10 points from the expected IQ for your income. And obviously there is enormous variability within each economic class, with some homeless people being smarter than most self-made billionaires.

Jewish ancestry & the IQ of Nobel Prize winners


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One of the most innovative ways to estimate the IQ’s of Nobel Prize winners (and other elite groups) has been to observe the percentage that are Jewish (or partly Jewish). Since high IQ is disproportionately common among Ashkenazi Americans, any achievement that selects for high IQ should also indirectly select for Jewish ancestry, so all else being equal, there’s some mathematical formula that allows ones to estimate a group’s average IQ from the degree of Jewish over-representation. Such calculations have been done by La Griffe du Lion and others.

La Griffe argued (if I understood him correctly), that since U.S. Nobel Prize winners and Americans with IQ’s of 139+, are both 27% Jewish, that the dumbest Nobel Prize winners has an IQ of 139, and from there he concluded that the average U.S. Nobel Prize winner has an IQ of 144. While an average IQ of 144 sounds plausible, La Griffe’s methodology made no sense to me because the IQ’s in a group (even a high achieving one) tend to be normally distributed, so I would expect a wide range of IQ’s rather than everyone bunched together above some ridiculously high threshold. So now would be a good time to revise his analysis with a radically different approach.

The correlation between IQ and Ashkenazi ancestry

Ashkenazi Jews are 2% of America and average IQ 113 while the average for all Americans is 100. If there were a perfect correlation between Ashkenazi ancestry and IQ, every single Ashkenazi American would be in the top 2% of IQ (130+) and thus the average Ashkenazi American would be in the top 1% (IQ 135). Since the average Ashkenazi American is not 35 points above the U.S. average, but rather 13 points above it, the correlation between Ashkenazi ancestry and IQ can be estimated by dividing 13 by 35, which gives 0.37. Of course this correlation falsely assumes that Ashkenazi ancestry is a normally distributed continuous variable that all Americans can be ranked on, when in reality it’s a discrete category that only a small minority fit into, but for our purposes, that probably doesn’t matter.

The correlation between g (general intelligence) and Ashkenazi ancestry

If Ashkenazi ancestry correlates 0.37 with IQ, and most IQ tests have a g loading around 0.85, then dividing 0.37 by 0.85 gives the g loading of Ashkenazi ancestry as 0.44. We should also correct for the fact that ethnic self-identification probably correlates about 0.9 with actual ancestry, so dividing 0.44 by 0.9 reveal the true g loading of Ashkenazi ancestry to be 0.49.

How Jewish are Nobel Prize winners?

According to this source, Jewish Americans are dramatically over-represented among U.S. Nobel Prize winners. They are 11% of Peace laureates, 27% in chemistry and literature, 38% in physics, 42% in physiology and medicine, and 53% in economics. Since only 2% of the general U.S. population is Jewish, these numbers imply that peace prize winners are 0.8 standard deviations (SD) more Jewish than average, chemistry and literature winners are +1.4 SD in Jewish ancestry, physics winners are +1.67 SD, physiology/medicine +1.8 SD, and economists are +2.07 SD

Estimating average IQ from average Jewish ancestry

In order to estimate the average IQ of the Nobel Prize winners, we must divide their degree of Jewish ancestry (expressed in SD units) by the g loading of true Jewish ancestry (0.49). We must then multiply the resulting Z score by 0.85 since that’s the g loading of a typical IQ test. After multiplying the Z score by 0.85, we multiply it by 15 and add 100 to convert to the IQ scale.

The smartest Nobel Prize winners are economists?

After doing the above calculations we get the following average IQ for Nobel Prize winners in different disciplines:

Economics: Average IQ 154

Physiology & Medicine: Average IQ 147

Physics: Average IQ 143

Chemistry: Average IQ 136

Literature: Average IQ 136

Peace: Average IQ 121

These numbers sound plausible. The only red flag is that physics laureates didn’t rank higher. I suspect that’s because Ashkenazi intelligence is verbally oriented, so using Ashkenazi ancestry as a proxy for IQ underestimates the ability of spatially oriented intellects. Had this analysis been done based on East Asian ancestry instead, physicists may have come out on top.

Social Class, Paul Fussell & the Lion of the Blogosphere


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Decades ago, scholar Paul Fussell wrote a book called Class which has been recently popularized by social class expert Lion of the Blogosohere. In it, Fussell divided American society into nine social classes. I found a description of those nine classes at

Top Out of Sight – Billionaires and multi-millionaires. The people so wealthy they can afford exclusive levels of privacy. We never hear about them because they don’t want us to.

Upper Class – Millionaires, inherited wealth. Those who don’t have to work. They refer to tuxes as “dinner jackets.”

Upper Middle – Wealthy surgeons and lawyers, etc. Professionals who couldn’t be described as middle class. I suspect this is the class to which I, an engineer, am supposed to aspire.

Middle Class – The great American majority, sort of.

High Proletarian (or “prole”) – Skilled workers but manual labor. Electricians, plumbers, etc. Probably not familiar with the term “proletarian.”

Middle Prole – Unskilled manual labor. Waitresses, painters. (In other words, my mom and dad!)

Low Prole – Non-skilled of a lower level than mid prole. I suspect these people ask “Would you like fries with that, sir?” as a career.

Destitute – Working and non-working poor.

Bottom Out of Sight – Street people, the most destitute in society. “Out of sight” because they have no voice, influence or voter impact. (They don’t vote.)

Fussell is quick to point out that class in America is not decided exclusively upon finances; it is also a matter of taste, what one does with one’s recreational time, what one reads, what colleges (if any) one has attended and how well one speaks.

There is a commentator at the Lion of the Blogosphere who calls himself “toos is god”. This person, as you can tell from his name, obsessively worships so-called TOOS (top-out-of-sights) and writes:

…I wonder who Natasha and Malia Soetero will marry. Will they marry ambitious Jewish guys, or will they marry what can be called the ‘black toos’? They cannot join toos for obvious reasons but they might try the next best thing.

Also, I have to say that all the intelligence debate is for nought. Being toos trumps all the intelligence in the world…

Bill Gates’ wife was known to be with people who were clearly in toos sphere, like a Wrigley heir about whom we do not hear too often. Gates might appear wealthier than the Wrigley heir, but I doubt he is more powerful.

In my humble opinion, this person is resentful of Gates and the Obamas and thus takes comfort in imagining some secret invisible social class that lords over them. But keep in mind, Fussell probably started writing his book around 1980, just a couple years before Forbes magazine began publishing their annual list of the 400 richest Americans, which made it almost impossible for the richest Americans to stay completely anonymous. Indeed some members of the Forbes 400 have actually sued to be kept off the list, but the judge ruled that the since the rich have so much influence, the public has the right to know who they are (in sharp contrast, Donald Trump sued a reporter for saying he wasn’t a billionaire).

But class is not just about money; while money, power, and class are all inter-correlated, they are (in my opinion) three different hierarchies:

MONEY: economic capital (income & wealth)

POWER: social capital, status, popularity, prestige; the sitting president is considered the most powerful man on Earth and is also virtually always tops Gallup’s most admired poll. Oprah is so worshiped she was elected the Greatest woman in American history, and is often described as the most powerful woman in the world. Reagan is so worshiped he was elected the Greatest American of all time, and was so powerful he served eight years as president, helped make America the sole super-power, had a vice president that served four years, a vice president’s son that served eight years, and forced the Democrats to become more fiscally conservative. So roughly speaking, being worshiped by Americans = power (conventionally defined)

SOCIAL CLASS: genetic & cultural capital ,if you come from a rich and powerful family, look intellectual (dark rimmed hipster glasses), sound intellectual when you speak or write, attended a prestigious college or simply display physical traits associated with progressive evolution (tall gracile physique) you will likely be embraced by the hoity-toity. Because high social class is less about extrinsic capital that can be acquired (money, power) but more about intrinsic traits and genetic pedigree.

Some people might define social class more broadly by combining all three hierarchies into one, but this seems pretty unscientific and arbitrary. I could be wrong, because I find this whole concept quite nebulous, but here’s how the Lion of the Blogosphere explained it (he seems to combine all three hierarchies, but note the emphasis on pedigree):

The key characteristic of the top-out-of-sight class is multiple generations of private school attendance. And we are talking about private schools attended by children of wealthy people, not crappy Catholic schools. Generally, in order for a person to be top-out-of-sight, he must have attended private school, and so did his parents, and so do his children.

The top-out-of-sight are not famous and do not have high-visibility jobs, because they have to be out of sight. Out-of-sight should not be taken too literally. Many of the top-out-of-sight are hiding in plain sight in places such as Manhattan.

The top-out-of-sight insulate themselves from proles. For example, if they live in New York City, then they live in a doorman building and they avoid subways and buses…

One does not have to be super-rich to be top-out-of-sight. At the bottom end of the top-out-of-sight, you just need to be able to afford private school for two children plus incidental expenses like vacations. Because the top-out-of-sight can have jobs of some sort (although never the kind where a boss yells at them and they have to punch a timecard), the amount of inherited money they need is not as high as commonly assumed. Their social capital allows them to get paid a lot more for their work than you might think given their lack of true value creation.

Masculine guys more likely to be Republican & the genetics of being gay


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Recently at the Lion of Blogosphere, commentator “First Ypres” (as he now prefers to be known) stated:

It’s pretty clear that the Republican Party is the party of the kids who weren’t cool in high school.

The host of the blog (The Lion), corrected him, explaining that jocks are actually more likely to be Republican.

Thinking back on all the jocks and nerds I have known over my life, it became clear to me that both men are right. Both jocks and nerds are more likely to hold certain strong conservative views. While it’s true that Silicon Valley types tend to vote Democrat, I think that’s only because their IQ’s are so high and IQ is correlated with liberalism. If you looked at nerds and non-nerds of equal IQ, the nerds might be far more Republican.

How can both jocks and nerds be conservative when they are typically thought of as being opposites? Because both jocks and nerds are extremely masculine. Jocks are physically and temperamentally masculine, while nerds are cognitively and intellectually masculine (i.e. Spatial IQ > Verbal IQ; Math IQ > Social IQ, enjoying chess & video games)

So if both jocks and nerds are Republican, who are the Democrats? Women and artsy/literary feminine guys. The kind who write poetry and joined the drama club in high school.

Does this mean liberal men are more likely to be gay? I don’t entirely think so, because there’s also the stereotype of a lot of Republican, religious, or hyper-macho homophobic guys being secretly gay. From an evolutionary perspective it would make sense for gays to support the most homophobic party they could because the more homophobia there is in society, the more gay men feel the need to conceal their identity by acting straight; the more gay men pretend to be straight, the more children they have (who genetically inherit both the genes for being gay and the genes for being homophobic).

In recent years, thanks to people like Richard Dawkins, our understanding of evolution has shifted from what’s good for the individual, to what’s good for specific genes. So a gene or allele that causes people to be both gay and homophobic would rapidly spread through the population because it would cause everyone who carries it to have more kids than usual to hide the fact that they are gay and it would create a culture where all its carriers had more kids.

So pumpkinperson has resolved the paradox of how being gay can be genetic despite the fact that gays have fewer kids. They are probably having TONS of kids, we just don’t know about it, because the gays who are having kids are the ones who self-identify as straight and go out of their way to show how straight they are by playing football and voting Republican. In other words, if you’re homophobic and live in a homophobic society, you don’t need to be straight to reproduce; social pressure is sufficient motivation. By contrast, the openly gay people are probably the most intelligent subset on average and these tend to be very liberal, perhaps especially if their sexuality was determined by prenatal events, not genes.

Estimating the IQ of Geniuses from their average brain size


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On page 124 of scholar Stephen Jay Gould’s The Mismeasure of Man, he writes about a fascinating era when men of eminence (culturally recognized Geniuses; Nobel Prize winners) donated their brains to science.

Some men of genius did very well indeed. Against a European average of 1,300 to 1,400 grams, the great Cuvier stood out with his topheavy, 1,830 grams. Cuvìer headed the charts until Turgenev finally broke the 2,000-gram barrier in 1883. (Other potential occupants of this stratosphere, Cromwell and Swift, lay in limbo for insufficiency of record.)

The other end was a bit more confusing and embarrassing. Walt Whitman managed to hear America singing with only 1,282 grams. As a crowning indignity, Franz Josef Gall, one of the two founders of phrenology – the original “science” of judging various mental capacities by the size of localized brain areas – weighed in at a meager 1,198 grams. (His colleague J. K. Spurzheim yielded a quite respectable 1,559 grams.) And, though Broca didn’t know it, his own brain weighed only 1,424 grams, a bit above average to be sure, hut nothing to crow about. Anatole France extended the range of famous authors to more than 1,000 grams when, in 1924, he opted for the other end of Turgenev’s fame and clocked in at a mere 1,017 grams.

While Gould doesn’t report the average eminent brain, a simple way to estimate it is to observe the range, from the largest Genius brain (Turgenev; 2021 g) to the smallest (Anatole France; 1,017 g), and take the midpoint: 1519 g. However as scholar J.P. Rushton has explained, brain weight increases by 9% postmortem so I will divide this figure by 1.09 to get the in-vivo weight which gives 1394 g. Now to convert brain weight to volume, you multiply by 1.036 which gives 1444 cm3

How does this compare to normal men of that generation? The average year and average age when these two eminent men died was 1904 and 72 respectively. Meanwhile data from the general population shows that British men who died in 1907 (average age 47) had a mean brain weight of 1372 g. But these men were born 28 years later (on average) so to make their brain weights comparable we adjust for age by noting that from age 25 to 80, brain weight varies negatively with age by 2 g per year, so general population British men of the same average generation as Turgenev/France would be 1316 g. Dividing this by 1.09 and multiplying by 1.036 reveals this generation of men had a mean volume of 1251 cm3, 193 cm3 smaller than the average Genius of that era. Since Rushton’s military data shows that the cranial capacity standard deviation (SD) in white men is 91 cm3, the average Genius had a brain 2.12 SD bigger than normal!

Corrected for reliability and range restriction, the true correlation between IQ and brain size is probably 0.5, suggesting the true correlation with g (general intelligence) is 0.53. This correlation is far from perfect, and suggests that the brain size of Geniuses regresses precipitously to the mean (see validity generations). To correct for this regression, we divide the average Genius brain size (+2.12 SD) by 0.53 which gives an average IQ on a hypothetically pure measure of general intelligence of 4 SD above white men (IQ 162)! However because the typical IQ test “only” has a g loading of about 0.85, Geniuses should regress 15% to the mean on an IQ test and average 153 when tested (assuming the test has sufficient ceiling). Indeed an important study of extremely eminent scientists found they had a mean tested IQ of 150.

Calculating your Reaction Time IQ using a user friendly Reaction Time test

Eminent scientist and intelligence blogger Bruce Charlton once blogged about converting reaction times into IQ score equivalents, and now that blogger alcoholicwisdom has told this blog about a really user friendly reaction time test at, it’s time to explore this idea further.


The average reaction time of those who take that test is 253 ms. In order to equate that to IQ, we need to know the average IQ of people who take that test. Well we can estimate the average IQ to be 117 because many years ago, a company called Braintainment sold a complex series of reaction time tests called “Thinkfast” and customers on their website had an average IQ of 117 based on a five-minute IQ test. Even though Thinkfast customers are not the same as visitors, it’s reasonable to assume that both populations have the same IQ, since they’re both self-selected internet users with an interest in reaction time.

Thus 253 ms = 117 IQ

Some might argue that you can’t just equate the two figures because there’s no reason to assume chronometric players will be equally self-selected for reaction time as they are for IQ. But what they’re really self-selected for is intellectual interests and the internet access to pursue them. Since this self-selection is g loaded, and since both reaction time and a 5 minute IQ test are probably both only moderately g loaded, it seems reasonable to equate them. In fact, this is a well known psychometric technique called equipercentile equating, and was used to norm the famous Mega test using SAT scores (see section 8.4.1 of the Prometheus MC Report for more details).

The next thing we need to do is equate the standard deviation for simple reaction time with the standard deviation for IQ. Scholar Michael Woodley and his colleagues have argued that the population standard deviation for simple reaction time in Western countries is 160.4 ms, a truly colossal figure. However scholar Arthur Jensen has shown that when you measure the mean reaction time repeatedly in college students (each one playing 20 times and taking the average simple reaction time for each student), most of the variability between individuals gets cancelled out and the standard deviation of the averaged out reaction times is only 29.23. The standard deviation for IQ in the general U.S. population is 15.

Thus, when taking your average reaction time from 20 tries:

29.23 ms = 15 IQ points

Some people might object that college students have a restricted range of reaction times because they’re selected for general intelligence. However because the correlation between reaction time and education is weak, and because even among college students, there is enormous range in education (some drop out their first year, others go on to get PhDs) it’s likely that college students are not a chronometrically range restricted population.

It should be noted that Bruce Charlton believes one’s best reaction time scores are more meaningful than one’s average scores, however we do not have stats for best performance, so average performance will have to do for now.

So now that we have these two data points, we can convert reaction time to the IQ scale.


Step 1: Make sure you are on a desktop or laptop computer with a clickable mouse (mobile devices give much slower reaction times)

Step 2: Go to’s reaction time test

Step 3: Play 8 warm-up tries to get practice. When you reach “Trie: 5 of 5”, it will ask you if you want to save your scores. Just ignore that question and keep playing until you reach “Trie: 8 of 5” (your 8th warm-up). You will notice your average reaction time being calculated on the screen. Ignore this because you are just doing warm-ups so your scores don’t count.

Step 4: Revisit the reaction time test on a fresh screen so that you can get a new running average. Now play 20 consecutive tries and record the average reaction time it calculates from all 20 tries. This will be your score.

Step 5: Go to the poll below to record your reaction time and observe the IQ equivalent. Don’t be depressed if your reaction time is terrible. Simple reaction time is just a crude physiological proxy for intelligence, much like brain size so I expect brilliant people to regress enormously to the mean and for many gifted people to have slow reaction times. Just as there were Geniuses like Einstein who had small brains, there will be Geniuses who have slow reaction times. Also, reaction time slows precipitously with age. If you’re older than the average person who visits, your IQ equivalent will be further depressed (severely so).

NOTE: The IQ conversions I discuss are just my own personal conjecture and have not been endorsed by (a website I have no connection to)

What is pumpkinperson’s IQ?


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Recently a new commentator named “alcoholicwisdom” (cool name btw) mentioned the wisdom of crowds. This is based on a famous experiment where a crowd of people were asked to estimate the weight of an animal and while most people were wrong, the average of all the estimates was close to perfectly accurate. This happened because error in both directions often cancels out.

Alcoholicwisdom thought it would be interesting to apply the wisdom of crowds to guessing IQ, so what better application of this concept then to have my readers guess my IQ. The best way to do this is in an anonymous poll since many people will be more honest when voting by secret ballot.

Please only vote if you feel you’ve read enough of my posts or comments to have a rough idea of how intelligent I might be (no point voting if this is the only post you’ve read). Also please take the poll seriously and answer honestly, and not based on whether you personally like or dislike me. Also, one of my readers actually gave me some IQ tests, so he’s not allowed to vote, because he has objective scores, and the whole point of this exercise is to observe the distribution of subjective IQ estimates. Also please vote BEFORE you read any of the comments, because the wisdom of crowds only works if each member of the crowd votes independently and is not influenced by the opinions of others.

Do Brain Size readers really have an average IQ of 147?


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My recent post about how readers of have an average IQ of 147 was damaging to the self-esteem of many readers. For example a reader named “Andrew” wrote:

I suppose I’m the dunce around here with an IQ of ~120!

Intelligence is relative, so even though an IQ of 120 is higher than 90% of the U.S. population, when you find yourself on a blog like this one where the average IQ is said to be 147, an IQ of 120 can feel extremely low.

Well the good news for all the “Andrews” out there is that my readers do not have an average IQ of 147 after all. That figure was arrived at using remarkabley indirect evidence. A poll I conducted found that the average reader was about 0.62 standard deviations taller than others of their demographic group, and since height is thought to correlate 0.2 with IQ, I simply dividing their average height (+0.62 SD) by 0.2, to estimate their average IQ to be 3.1 SD above the mean (IQ 147).

There were a couple problems with this however. For starters, as more readers have started to vote in the height poll, it seems the average reader is 0.43 SD taller than normal, not 0.62 SD as previously estimated. Secondly, while 0.2 is the correlation between IQ and height, what I really want is the correlation between height and g (general intelligence) and I want it corrected for reliability. This figure would be about 0.26.

So now with the revised height (+0.43 SD) divided by the true g loading of height (0.26), it seems Brain Size readers have an average general intelligence of 1.65 SD above normal. In other words, Brain Size readers average an IQ of 125. This is a far more believable figure than 147, which is about what you’d expect from the average academic Nobel Prize winner.

Many people are confused by why I divided the height of my readers (+0.43 SD) by the true g loading of height (0.26), instead of just multiplying it. For example, NBA players are ridiculously tall (perhaps +3.88 SD taller than other American men in their age group). If I wanted to estimated the average IQ of NBA players from their average height, would I divide their height by the g loading of height? If so, their estimated intelligence would be +14.92 SD (an average deviation IQ of 324 making the average NBA player more than 100 IQ points smarter than any person who ever lived!) So instead of dividing their height (+3.88 SD) by 0.26, I would multiply, which gives an estimated intelligence of +1 SD (IQ 115).


Test your reaction time


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Reaction time is perhaps the most physiological, culture fair measure of intelligence. If your reaction time is slow, it means your brain is probably slow, and you’re deficient in a major component of intelligence. Of course reaction time is only moderately g loaded, so don’t be too depressed if you take this test and find out your reaction time is way slower than you thought. The great thing about this test is that it averages your 5 scores for you. Maybe practice for about five minutes to make sure you’re used to the test and know how it works, and then once you feel comfortable, do an official five trials and consider the average the computer calculates, your official average reaction time.