Job performance is supposedly one measure that validates the construct of IQ tests since they correlate so highly with IQ tests (Schmidt et al, 1986). However, there are problems with the methods used to get the high correlations (sometimes doubling correlations, there are also questions to the robusticity of the studies meta-analyzed); corrections used have to make a number of assumptions; uncertainty of the interpretation of what the supposed IQ and job performance correlations mean; other non-cognitive factors may also explain differences in job performance. Most surprisingly, intelligence test scores did not predict promotion to senior doctor and intelligence does not predict careers.
Job performance and IQ
Does IQ really correlate around .5 with job performance like is so commonly stated? There are a number of problems citing such the commonly used meta-analyses for evidence that IQ does indeed predict job performance.
Richardson and Norgate (2015) show that one should use caution when interpreting the results of IQ and job performance on the basis of numerous criteria. It is important to note that job performance is rated by supervisors, which is, of course, a problem since supervisors tend to be subjective in their ratings. Further, supervisor ratings have low correlations with work performance, while work knowledge has a correlation of around .3 (Richardson and Norgate 2015; Richardson, 2002). So, one of the main things that the correlation hinges upon is strongly subjective.
However, one of the most important things to note here is that the validation of IQ tests is relied on with correlations with other tests. For instance, blood alcohol and level of consumption are valid constructs. The higher your blood alcohol is, the more alcohol you consumed. There is no such validity for the construct of IQ—except correlations with other tests—which is a huge problem. This goes back to the fact that there is no individual theory of intelligence differences (Deary, 2001: 14) and no neurophysiological theory of g (Jensen, 1998: 257).
So IQ tests don’t have the same construct validity that other models that describe biologic/physiologic functions do; hundreds of studies before the 70s showed low correlations between IQ and job performance; corrections for error make a lot of assumptions; the common claim that the IQ/job performance correlation increases with more complex jobs is not observed in more recent studies; and there is great uncertainty in the interpretation of the IQ and job performance correlation, due to the fact that there is no construct validity to IQ tests. This goes back to the question: What is it that IQ tests test (Richardson, 2002)? Is it the ever-elusive general factor of intelligence? I’m skeptical there.
Richardson (2017) writes:
The committee described the differences as “puzzling and somewhat worrisome.” But they noted how the quality of the data might explain it. For example, the 264 newer studies have much greater numbers of participants, on average (146 versus 75). It was shown how the larger samples produced much lower sampling error and less range restriction, also requiring less correction (with much less possibility of a false boost to observed correlations). And there was no need to devise estimates to cover for missing data. So, even by 1989, these more recent results are indicative of the unreliability of those usually cited. But it is the earlier test results that are still being cited by IQ testers. (pg. 89)
IQ and job performance correlations are also substantially weaker in other parts of the world, such as the Middle East and China, where motivation and effort explain school and work performance and not cognitive ability (Byington and Felps, 2010). So, again, caution is to be taken when interpreting any IQ and job performance correlation, as well as—most importantly—asserting that higher IQ means better job performance.
In his 2015 book Intelligence in the Flesh, Guy Claxton wrote:
We saw earlier that Google is not impressed by people’s track records of success, but is equally sceptical of high IQs. Laszlo Bock, the senior vice-president in charge of ‘people operations’ – the head of HR – says: ‘For every job the No. 1 thing we look for is general cognitive ability, and it’s not I.Q. It’s learning agility. It’s the ability to process on the fly.‘ Behind the ability to learn quickly lies what Bock calls ‘intellectual humility.’ You have to be able to give up the knowledge and expertise you thought would see you through, and look with fresh eyes. People with a high IQ ofen have a hard time doing that. They are certainly no better than average at tolerating uncertainty or being able to adopt fresh perspectives.
Now that we know to take caution when speaking about the IQ and job performance correlation, what do IQ tests say about success as a doctor?
Doctors and IQ
Since becoming a doctor is so demanding and takes a lot of time and motivation to complete a doctoral degree, most rightly assume that it takes a higher than average intelligence to acquire these accolades and become a medical doctor. However, reality is more nuanced.
McManus et al (2003) put forth three hypotheses: 1) the achievement argument: A-levels ensure maximum competence on sciences which are basic to medicine (biology and chemistry); 2) the ability argument: Academic success depends mainly on cognitive ability; and 3) the motivation argument: Using A-levels is effective because it University education not only reflects intelligence but motivation and good, consistent study skills.
There is evidence that IQ is irrelevant to becoming a doctor and that it did not predict dropping out of the program, career outcome, amount of research publications published, or stress, burnout and satisfaction with taking a career in medicine (McManus et al, 2003). Diplomas, higher academic degrees, and research publications were significantly correlated with personality.
McManus et al (2003) write:
Intelligence did not independently predict dropping off the register, career outcome, or other measures.
Intelligence does not predict careers, thus rejecting the ability argument. A levels predict because they assess achievement, and the structural model shows how past achievements predict future achievement.
And on the causes for dropping out:
All 511 students registered with the General Medical Council, but only 464 were on the 2001 Medical Register. The 47 doctors who left the register (a mean of 11.1 years after qualifying; SD 5.9; range 2-23) had lower A level grades but not lower AH5 scores (table A, bmj.com); see http://www.bmj.com for ROC analysis. Two doctors subsequently returned to the register. Of the remainder, three had died, contact details were available for 35, and no information was available for seven.
So lower intelligence scores were not the cause for dropping out.
McManus et al (2003), however, could not distinguish between the motivation and achievement argument, but falsified the intelligence argument (Hypothesis 2 was falsified, but not 1 and 3).
This was also replicated by McManus et al (2013), where they should that IQ scores did not predict promotion to senior doctor. A-level scores, yet again, predicted success better when it came to doctoral success.
The relationship between IQ and job performance is not as clear-cut as most would like to believe. One of the most important factors there, in my opinion, is the subjectivity of supervisors on the performance of their workers. Numerous factors could influence a supervisors’ view of an individual, biasing the supervisor to a high rating. Furthermore, the corrected correlations are a problem. More recent analyses show a correlation of .25 (Richardson, 2017: 89).
Perhaps more importantly, two studies show that there is no predictive effect on job performance when it comes to IQ for doctors (McManus et al, 2003; McManus et al, 2013). They show that A-level scores predict success better, with personality variables mediating other relationships—not IQ scores.
The fact of the matter is, job performance and IQ is on shaky ground since IQ tests are not constructed valid, and the job performance ratings are based on supervisor ratings which are highly subjective. Analyses in other locations around the world show that IQ does not predict job performance, however, motivation and effort do. IQ does not predict a doctor’s job performance; job performance tests do not prove the validity of IQ tests.
IQ does not predict a doctor’s job performance; job performance tests do not prove the validity of IQ tests.
[Edit: I have come across more data on doctors IQ. Some studies show that complaints by patients on their doctors are related to infractions. Perry and Crean (2005) show that the average IQ for a doctor is 125. They also state that neurocognitive impairment may be responsible for 63% of all physician related adverse events. This same observation is also noted in other studies (Pitkanen, Hurn, and Kopelman, 2008; Lauri et al, 2009; Kataria et al, 2014). Also of note is that these papers—to the best of my knowledge—do not explore the role of stress in cognitive decline. Though Pitkanen, Hurn, and Kopelman (2008) note that depression, PTSD, amnesia, transient global amnesia, alcoholic brain damage, frontotemporal dimentia, dimentia, alzheimer’s disease, vascular dimentia, and post-traumatic amnesia (PTA) influence cognitive decline in doctors.
Veena et al, (2015) show that 88 percent of medical students had near average intelligence, putting in 6 hours a day of studying, while 10 percent of students had above average IQ, spent less time studying but were sincere in their classes.
Veena et al (2015) conclude:
Students with near average IQ work hard in their studies and their academic performance was similar to students with higher IQ. So IQ can`t be made the basis for medical entrance; instead giving weight-age to secondary school results and limiting the number of attempts may shorten the time duration for entry and completion of MBBS degree.
So students with average intelligence work just as hard (if not harder) than people with above average IQ and have similar educational achievement. This shows that IQ can’t be the basis for medical school entry.
This is a really interesting matter and I will cover it more in the future. I’ve been wondering for years if there is data on physician/doctoral malpractice and race I have yet to come across any papers on the matter. If anyone knows of any, please leave some citations.]
Isn’t IQ and personality two seperate evolutionary phenomenas? Couldn’t this explain why it would not explain job performance? As you can have someone high IQ’d but be lazy? I remember Rushton showing that the general factor of personality wasn’t g-loaded (admittedly, I don’t know much about GFP and rather it’s valid or not), so could this possibly be any part of it?
Also, wouldn’t this disprove that an IQ threshold is needed to X, Y and Z job fields?
IQ would have to be a proven evolutionary phenomenon, first and foremost.
I haven’t read about the GFP in some time but I believe you’re right there. I’ll get back to you this afternoon. This could play a part in it, however as the studies I’ve cited have shown, for doctors, personality matters more for certain things, like academic publications, diplomas and degrees.
I am unaware of other fields, but it’s clear that in a sample of doctors and doctoral students, IQ doesn’t mean too much.
Thanks a lot for an interesting entry. My reaction to the richardson study when you have first linked it was “wow, interesting remarks, a lot of valid concerns and interesting points. Let’s wait until other researchers will comment upon it”. Nevertheless, while Richardson raises many excellent points, I prefer to be cautious.
I’d also want to add two minor points: one, that iq/job performance relation depends also on the assumptions used to establish the relation, as reported by Lang et al 2010 “General mental ability…”.
I admit I have not read their original meta-analysis, only the “in press” version (which might be different from the final paper published and has all the figures and tables missing) and the recap of Lang’s work in Kell, Lang 2017 “Specific abilities in the workplace…”).
When using a method assuming the “g” exists (which they call “GMA”, general mental ability), then “g” arises as the most important predictor of the job performance (even though the relationship is weak), and specific abilities do not add much explanatory power.
However, when they use a different method with the same bunch of data, the results are that while “g” is usually relatively important (and is placed above several other abilities), the other abilities may be relatively more important.
The Lang et al warn the reader from relying only on one perspective and theoricize that new studies may get fundamentally different results only because they use different assumptions, while they could get the results more in line with the previous literature if they would use the traditional assumptions (e.g if there is a common variance explained by two abilities, then should this variance be attributed to “G” or no?).
The Lang’s metanalysis is amongst those quoted and criticized by Richardson et al; however Lang’s metanalysis does not suffer from all of the possible sources of bias mentioned by Richardson, namely not from “variety of tests”, “majority are military personnel”, it does not rely only on supervisor rating (it includes also oral examinations, written exams, on-the-job performance assesment – though the second is related to richardson critique of “of course written tests predict performance in written tests”). Unfortunately, only 5 of the studies included are post 2000.
My second minor point is that Lang’s metanalysis confirms the relationship between job complexity and IQ – “modestly stronger” relationship between GMA (I presume: “g”) and job performance. Similarly Salgado et al; Richardson and Norgado knows that studies (they quote them in the paper!), but decided not to quote them in the section on job complexity (which is understandable, they have a reason to believe they face the same issue as Hunter et al study). This creates an impression (I assume, not intentionaly) that the only metanalysis which found the relationship is Hunter et al. However, we have three metanalysis, for USA, for Europe and for Germany specifically, all finding similar relation.
That were the two minor points with Richardson paper; now about the doctor’s performance. While it seems that the evidence that IQ does not predict much of doctor’s success, do you also believe that anyone (regardless their IQ score) can become a doctor ie. there is no “IQ threshold”, below which a succesful career as a doctor is highly improbable?
It’s very weak. Lang et al (2010) write:
Results revealed that GMA accounted for 10.9% to 28.6% of the total variance explained in job performance and that GMA was not consistently the most important predictor.
Though the “not consistently the most important predictor” line is for jobs with low complexity (pg 623).
And write on pg 631:
Depending on the relative importance analysis approach and job complexity, GMA was not always the relatively most important predictor in our analyses. The most common finding was that GMA and a couple of narrower cognitive abilities were about equally important. Thus, the findings suggest that GMA frequently does not have a statistical advantage over several narrower cognitive abilities, and the findings consequently provide an empirical basis for using measures of narrower cognitive abilities instead of GMA measures in personnel selection.
You summarized the paper really well by the way. Some problems though:
They cite the Germany study as evidence that the correlations double under correction, with low correlations before said correction.
Lang et al (2010) also suffers from ‘hypothetical estimates’ as Richardson and Norgate (2015) point out.
all finding similar relation.
They’re flawed. Lang et al (2010) used supervisor ratings as well.
Which meta-analysis was the one done for Europe?
No, obviously not (since lower scores may represent some mental defects). However, in a sample of doctoral students, IQ, clearly, does not matter for educational attainment, motivation and studying.
I’ll reply more to this comment later.
You outed yourself as a Leftist. Especially for quoting a book that quotes the Leftist Google (see James Damore).
Also, the Middle East has an average IQ in the 80s. China’s average is significantly higher but surely has less variation than Europe (less morons but less geniuses). There are so little high IQ individuals in the MENA that it’s hardly a surprise that you won’t see any major gaps among workers.
I’m not a leftist. I have right wing views. Nice assumption. I quoted a book talking about how Google hires employees and it isn’t based on IQ. Must mean I’m a leftist.
Am I a leftist because I love reading? Or is it because I’m a contrarian?
The fact of the matter is, as seen in Byington and Felps, for those two areas IQ doesn’t predict job performance and that motivation and effort explain school and work performance in those areas.
China isn’t really too nice a place even with their “high IQ” as cited by Lynn et al. Check out Afro’s data on China.
Trying to deny IQ is a thing and minimize its impact is a traditionally Leftie stance.
And Google is infested with Leftists. See how James Damore was fired for privately writing a memo noting how the lower performance of select victim groups like women as programmers and overall significantly lower presence in STEM (the domain of European, East Asian, and South Asian males) just might have a biological aspect to it.
Again MENA has an average IQ in the 80s. China is higher but has less variation than Europeans. For your post and that study to stand, Chinese and MENAs would need to perform highly in the West. And while Chinese with other East Asians perform well enough to be labeled as Model Minorities, that’s not really the case for MENAs.
Also, you could try looking at more than just job performance. Try looking at violent criminality, patents, nobel prizes in actual science, makeup of the world’s richest…
I have no doubt China has its issues. That said, I doubt it’s as dysfunctional as African or South American countries.
That doesn’t make me leftist. I like facts nd data sans ideology. I didn’t even bring up politics in the article. Why are you bringing it up?
I am aware of this, but it’s irrelevant to the quote provided from Laszlo Bock.
The average IQ of the Middle East is irrelevant here. The claim is that it doesn’t predict work performance in that location. The claim that East Asians also have less variation is a myth with no empirical data. Richard Lynn has said as much.
I’ve covered some of this (though Nobel Prizes have huge biases), but it’s irrelevant to IQ and job performance.
I’m unaware. The fact of the matter is, China’s supposed IQ doesn’t lend credence to the fact that high IQ supposedly leads to good traits as is supposed. There is a ton of dysfunction in the Chinese government.
By the way Maldo, Ed Yong argues that Nobel Prizes are an “absurd and anachronistic way of recognizing scientists for their work. Instead of honoring science, they distort its nature, rewrite its history, and overlook many of its important contributors.”
Wouldn’t range restriction explain lower IQ correlations for doctors’ job performance because high medical school entrance requirements and demanding academics create a relatively small, nonrepresentative, highly skewed sample of cognitive talent?
Also that. Controlling for pandering to minorities and women would point to doctors and other white collar professionals being above average in intelliegence. Jordan Peterson actually showed info on this.
McManus et al (2013) write:
However, individuals within the pool of applicants who fail to get in to medical school because of poor A-level grades never take medical school examinations, so we can never find out whether, had they been allowed in, they would have done as badly as they did in their A-levels, or whether they would have confounded expectations and done well. This restriction of range means that in the selected group (those who enter medical school) the correlation of the selection measure (for example, A-levels) with the outcome measure (for example, first year medical school examinations) will necessarily be weaker than would be the case if performance were to have been assessed across the whole range of medical school applicants. That situation could only be assessed empirically if entrants were to be a random, representative sample from the pool of all applicants, with A-level grades at all levels of achievement. Statistical solutions to the problem of range restriction have been explored for many decades  and the problem is now statistically tractable [6, 7], so that validity coefficients for selection as a whole (so-called ‘construct validity’) can therefore be calculated.
The Academic Backbone: longitudinal continuities in educational achievement from secondary school and medical school to MRCP(UK) and the specialist register in UK medical students and doctors
McManus et al (2013) also write:
If A-levels do account for 65% of variance, then the remaining 35% of variance must be accounted for by other, non-academic factors, measurement error, range restriction and right-censorship having already been taken into account). Just as in astrophysics, ‘dark matter’ and ‘dark energy’ are posited to balance various theoretical equations, so medical student selection must also have its ‘dark variance’, whose nature is not yet properly characterized, but explains perhaps a third of the variation in performance during training. Some variance probably relates to factors which are unpredictable at selection, such as illness or other life events, but some is probably also associated with factors such as personality, motivation or study skills.
Construct-level predictive validity of educational attainment and intellectual aptitude tests in medical student selection: meta-regression of six UK longitudinal studies
In medical school entrants, IQ has no predictive power.
On sex and ethnic differences, McManus et (2013) write:
Males underperformed somewhat at GCSE, and taking that into account, did slightly better at A-level. Males performed better at BMS examinations, but then performed less well on clinical assessments, while once again performing better at MRCP(UK) Part 1. Non-white participants had slightly higher A-level grades, although that was not significant after taking sex into account. Non-white students underperformed on both BMS and clinical assessments, but had equivalent performance on MRCP(UK).
Do you have the source for Peterson’s claim?
I will be editing this article this afternoon as I have come across more data on doctor intelligence. Some studies show that lower neuropsychological ability is related to more complaints from patients, however one analysis shows that people with average IQs performed just as well in regards to academic performance as people with above average IQs.
IQ isn’t even used as a proxy for employment, so of course there isn’t a relationship. You don’t get offered a residency because of your IQ 90% of the time your employed don’t know your IQ.what is the point of this article?
Your employer doesn’t**??
Irrelevant since Hunter et al state around a .5 correlation between IQ and job performance. Which has a ton wrong, as I’ve covered.
There isn’t a relationship because job performance is more than IQ/g (whatever they are/test).
Irrelevant. IQ supposedly tests some as-of-yet-known so-called physiological process. So those who score higher on IQ tests should show more of whatever physiological process IQ/g supposedly measures.
As I’ve shown on the Indian study, 100 IQ med school students had similar educational attainment to those with higher IQs (80 percent of the sample had around an average 100 IQ and 10 percent were above average). Veena et al (2015) conclude that: “IQ can`t be made the basis for medical entrance; instead giving weight-age to secondary school results and limiting the number of attempts may shorten the time duration for entry and completion of MBBS degree.”
“IQ can’t be made the basis for medical entrance”, meaning that, at least in a sample of doctors, IQ doesn’t matter.
1) to show that IQ is unrelated to job performance and that huge caution should be taken while reading studies that suggest a strong link and 2) at least in a sample of doctors, IQ is irrelevant to becoming a doctor, as well as a senior doctor.
It’s not irrelevant, how would your employer know your IQ unless you actually gave it to them? The studies and by extension your article are all pointless. It says nothing about actual performance between occupations are you seriously suggesting the surgeon General has a lower IQ than the janitor who cleans the floors? I incredibly doubt that the participants within the study varied by more than an sd. It’s fucking obvious that variation within an occupation will be due to motivation and hardwork than IQ and this is because within that occupation IQ will have low variation.
High IQ (supposedly) explains job performance. So, it is logical to deduce that if it does explain a large variation in job performance then the brighter should be more likely to have better jobs. Employers do not need to know IQ test scores; in the case of the study I cited in my previous comment, it did not explain work ethic/achievement.
Not at all.
88 percent had average IQs and 10 percent had above average IQs (in Veena et al, 2015; haven’t located the study yet to get more info).
I think it’s more nuanced than that. Though I cannot comment further until I read Veena et al (2015).
So you agree with the article, good to know.
But you already cited a low correlation between supervisor opinion and actual work knowledge. So no. Employers don’t use IQ as criteria for employment to begin rendering your article pointless, I do not agree with the ideaological assumptions it rests upon. This argument is based off a strawman. Furthermore job performance cannot be dictated by IQ if the occupation itself does not have high variation in IQ scores. IQ will therefore be a better predictor of occupation, not actual performance within the occupation.
It’s illegal for any company to us IQ testing as a criterion to begin with. Claim 1: IQ test scores DO explain some variation in job performance (however small). Claim 2: Though, within a specific field do not identify who will get promoted in a given field, this example being senior doctor. Therefore, IQ scores do not explain variation within a given profession, this example being doctors. I see that you already agree with the argument.
P1: IQ test scores explain variation between jobs and who gets what job.
P2: IQ test scores should, therefore, predict variation within occupations as well.
P3: IQ test scores do not test motivation/expertise, so they leave a lot of cognitive (and non-cognitive) variables out of it.
C: IQ test scores do not explain variation within doctors/doctoral students.
Which are? Direct quotes please.
Why attribute ideological assumptions to my article? Have I accused you of any ideological leanings in this conversation? Please show me the same respect and let’s just discuss the data. Thank you.
One study cited showed ‘average’ IQs with ‘above average’ IQs (88 percent and 10 percent respectively). Though, a someone who believes that IQ tests are so important to job performance, it should dictate the ‘cream that rises to the top’, so to speak.
Average IQ for a medical doctor is 125 (see cite in article). However, I showed that average IQ people can and do do well in medical school, just as well as those with higher IQs.
I agree with you by the way. IQ predicts (some) job performance (however small), but it does not predict success within a given profession (doctors). I don’t think I argued that IQ is meaningless for all professions. Just that it 1) does not predict job performance and 2) it does not predict promotion to senior doctor.
“Most of the medical students had near average intelligence (88.3%)”
What does this mean? Did most of them have average intelligence in the sense that their IQ’s were near 100? Or was that the average IQ of doctors (reportedly around 125). I can only assume the latter, as the former expectation would be quite ludicrous.
I find it hard to believe (certainly in the developed world) that there were ANY medical students with IQ’s of, say, 95, extremely few with IQ’s of 105, and maybe a handful with IQ’s of around 115.
I submit that there is a fairly high threshold IQ to obtaining the opportunity to becoming a medical student/doctor. That’s not the same thing as saying “for doctors, IQ has no effect on job performance”.
So IQ has a HUGE effect on whether or not you get to be a medical student and ultimately a doctor. Once you get there, other things are more important to job performance.
Perhaps you should have made this clear in your article? Maybe something along the lines of “Potential medical students must, in general, have a threshold IQ of around 125 to be able to become a doctor, but once qualified it has been found that IQ has no relation to job performance”.
There is no such thing as a threshold or an IQ that is necessary to a given outcome, except getting in high IQ society.
I can certainly agree there is no hard and fast FIXED threshold to be able to qualify to study medicine.
Within the context of the “developed world’, however, it is simply not factual to suggest that persons with “average” or “below average” IQ could ever hope to qualify to study medicine in the first place, far less to become a doctor.
Again, I ask, based on what measurements does Veena et al (2015) conclude
“Most of the medical students had near average intelligence (88.3%)”
or indeed “10% of the students had higher IQ”
We at least know that this is not a “developed world” journal – it’s from India, and therefore may define “average intelligence” differently from our definition (generally, and IQ of 100).
But of course it’s not defined. For all we know “close to average intelligence’ means anywhere within 2SD’s of the average, and we would then be unsurprised to find the majority of the students clustered towards the top end of the range (which presumably might be different from 125, since we are in India).
It might help also if you could also cite a few studies from the “developed world”.
The average IQ for a doctor is 125 – that’s cited in the post, so the writer must (at the very least) not disagree with that number – close to 2SD’s from average.
So, notwithstanding the FACT that a high IQ is required to qualify as a doctor, we do seem in agreement that the job performance after that is not necessarily related to that doctor’s IQ.
Click to access ijcmph2015v2n3p275.pdf
The study would imply IQs near 100, though the range they used to categorize the numbers were 84-114. My guess could be they were closer to 114 as you suggested in regards to SD.
“Within the context of the “developed world’, however, it is simply not factual to suggest that persons with “average” or “below average” IQ could ever hope to qualify to study medicine in the first place, far less to become a doctor.”
That may depend on their personality as a student, that is in actually completing coursework and interest rather than reliance on abstract thinking alone, or further more what kind of medical career they may aim for aside from being a doctor.
“It might help also if you could also cite a few studies from the “developed world”.
The average IQ for a doctor is 125 – that’s cited in the post, so the writer must (at the very least) not disagree with that number – close to 2SD’s from average.”
Exactly what effect do you expect to make the association different in developed nations, standards in coursework? That could influence the correlation if Med education in Indian Universities or the specific universities observed in the studies are particularly different.
“So, notwithstanding the FACT that a high IQ is required to qualify as a doctor, we do seem in agreement that the job performance after that is not necessarily related to that doctor’s IQ.”
“I submit that there is a fairly high threshold IQ to obtaining the opportunity to becoming a medical student/doctor. That’s not the same thing as saying “for doctors, IQ has no effect on job performance”.
That’s not what he said, he said predictive effect.
“Perhaps more importantly, two studies show that there is no predictive effect on job performance when it comes to IQ for doctors (McManus et al, 2003; McManus et al, 2013). They show that A-level scores predict success better, with personality variables mediating other relationships—not IQ scores.”
Thanks for the link, which not surprisingly supports my statement in regards to the requirement of high IQ for medical students in general.
Can we just stipulate that requirements for entrance into a “government autonomous medical college, in central India” bears little comparison to requirements for entrance to any medical college in the US, Canada or Britain. We know this for certain because when an Indian doctor, for example, emigrates to one of these countries, he/she is required to be certified in that country in order to practice medicine.
Despite the fact that the US and Canada are experiencing a shortage of doctors, and are desperate for relief, many foreign doctors are unable to transition because of the higher standards expected (for doctors trained in other countries, fewer than 40 percent of those who apply for a US residency are accepted).
The IQ test used in the study was an online one, and hardly an accepted source for accurately measuring IQ . Extraneous circumstances at time of testing would easily account for the fact that a very small number of students (5/300) had a measured IQ of below 85. Given the wide parameters considered “normal”, we really have no idea how the students in the “normal” IQ cohort were clustered.
We do know that the average IQ in India is between 80 and 85. So it’s more than peculiar that this study is using an IQ of 100 as baseline average. In fact, a quick mathematical calculation (even including the 5 students supposedly below IQ 84) shows that these Indian students have an average IQ more than 2SD above the average Indian IQ.
Beyond mentioning that this “study” is certainly looking like a bit of dodgy one on which to hang one’s hat, I rest my case. Suggesting that a student with an IQ of below (say) 100 can overcome a low IQ by virtue of their “personality as a student” to aspire to be a medical doctor is simply not dealing with reality.
As for the statement about “what kind of medical career they may aim for aside from being a doctor”, I should note that trying to change the subject is clearly a sign that one is losing an argument.
“Thanks for the link, which not surprisingly supports my statement in regards to the requirement of high IQ for medical students in general.”
“Can we just stipulate that requirements for entrance into a “government autonomous medical college, in central India” bears little comparison to requirements for entrance to any medical college in the US, Canada or Britain. We know this for certain because when an Indian doctor, for example, emigrates to one of these countries, he/she is required to be certified in that country in order to practice medicine.”
That’s what I figured when I suggested it.
“Despite the fact that the US and Canada are experiencing a shortage of doctors, and are desperate for relief, many foreign doctors are unable to transition because of the higher standards expected (for doctors trained in other countries, fewer than 40 percent of those who apply for a US residency are accepted).”
“The IQ test used in the study was an online one, and hardly an accepted source for accurately measuring IQ . Extraneous circumstances at time of testing would easily account for the fact that a very small number of students (5/300) had a measured IQ of below 85. Given the wide parameters considered “normal”, we really have no idea how the students in the “normal” IQ cohort were clustered.”
Fair enough, granted however I’ve read of findings on students that found higher correlations with personality indicators as was found with doctors, but not Med students.
“We do know that the average IQ in India is between 80 and 85. So it’s more than peculiar that this study is using an IQ of 100 as baseline average.”
Not necessarily, 100 iq is typically held as a baseline and psychometrically speaking India is a country noted with having a large amount of those below 100.
” In fact, a quick mathematical calculation (even including the 5 students supposedly below IQ 84) shows that these Indian students have an average IQ more than 2SD above the average Indian IQ.”
Which is likely influenced by those with more resources, and higher IQs, having more access to these institutions, but that doesn’t necessarily negate the point of the lack of association with academic performanced.
Your points on the IQs being online however would.
“Beyond mentioning that this “study” is certainly looking like a bit of dodgy one on which to hang one’s hat, I rest my case. Suggesting that a student with an IQ of below (say) 100 can overcome a low IQ by virtue of their “personality as a student” to aspire to be a medical doctor is simply not dealing with reality.”
Where did the author mention below average students achieving? RR was only dealing with the association of IQ with performance within a career and student distribution.
“As for the statement about “what kind of medical career they may aim for aside from being a doctor”, I should note that trying to change the subject is clearly a sign that one is losing an argument.”
I’m not having an argument or trying to change the subject, I’m only adding points to your comment., two of which addressing the differences in national standards and clustering of “normal” IQs agreeing with your own.
As for my statement, not everyone who studies medicine necessarily aims to be a doctor so that could influence the variation in IQ. Why that signals that I’m “losing” just comes off as bizarre.
See medical occ. at the bottom.
I’ve looked for a study that uses an actual “average” (100 iq) sample, a none online test (Weschler’s) and students from a developed country.
Though still done in India, it uses better methodology. This uses EQ as well, though this was found to be different in Malaysia.
This maybe consistent with RR’s point of IQ and performance varying in different countries, though strength in yours of it’s relevance in developed countries.
A lot of words but no real focus. So lets cut to the chase-
Racerealist: “There is evidence that IQ is irrelevant to becoming a doctor…”
Afrosapiens: “There is no such thing as a threshold or an IQ that is necessary to a given outcome, except getting in high IQ society”
I believe that I have pretty conclusively shown that these statements are just plain wrong. Nothing so far, and certainly none of the studies cited, challenges that conclusion.
Racerealist’s unsupported statement about IQ being irrelevant to becoming a doctor stands out like a turd in a punchbowl in an otherwise mundane discussion centred around job performance AFTER graduation as a doctor and its relationship (or lack thereof) to IQ. Perhaps, in retrospect, he might like to delete, or at least “clean up” that statement, which neither of the McManus studies cited supports.
A high IQ is essential for becoming a doctor. To assert otherwise would be to ignore facts/reality and/or expose your bias towards the concept of IQ itself.
” lot of words but no real focus.”
Mainly because I wasn’t trying to make this an argument, my only points where I disagreed were the author’s point and the role of IQ variation in med students being influenced by their career prospects.
“So lets cut to the chase-
Racerealist: “There is evidence that IQ is irrelevant to becoming a doctor…”
Afrosapiens: “There is no such thing as a threshold or an IQ that is necessary to a given outcome, except getting in high IQ society”
I believe that I have pretty conclusively shown that these statements are just plain wrong. Nothing so far, and certainly none of the studies cited, challenges that conclusion.”
Since we were discussing the author’s words, I’m unsure why you bothered citing Afro. Regardless, RR did post evidence of a threshold of IQ for Doctors but I see how that clashes with his statement of IQ’ relevance.
Given his points being elaborated with Melo, distinguishing it’s between and within careers, he likely mistyped.
“Racerealist’s unsupported statement about IQ being irrelevant to becoming a doctor stands out like a turd in a punchbowl in an otherwise mundane discussion centred around job performance AFTER graduation as a doctor and its relationship (or lack thereof) to IQ. Perhaps, in retrospect, he might like to delete, or at least “clean up” that statement, which neither of the McManus studies cited supports.”
He has done so before so this isn’t unreasonable.
i’m sure you know this, but so many of these studies would show a very strong relationship between IQ & performance if the whole range of IQ could be doctors – if your doctor had an IQ of 65, your doctor would be bad. the correlation between IQ (“g”) is very high w/ job performance, but since we don’t let low IQ people do those jobs it attenuates/hides the relationship. 1 must think scatterplot – then realize the whole left side of the scatterplot is chopped off. only a little bit of the right side remains. same w/ say ACT & college GPA – let retarded/intel. disabled people in, then you’ll see how LARGE that correlation really is!!
I agree. Though I did state that within a sample of doctors that IQ didn’t mean anything for promotion to senior doctor (see McManus et al 2013). The Indian study I cited stated that 88 percent of the students had average IQ while 10 percent were above average.
Though for all jobs, IQ doesn’t really matter. See Richardson and Norgate (2015). The literature on IQ and doctors is scarce, most of the literature is on “emotional intelligence”.
Of course allowing retarded and disabled people in who can’t do the work would raise the correlation. But for people who are motivated to become doctors, test scores and previous school history matters more than raw IQ (whatever it tests).
“The Indian study I cited stated that 88 percent of the students had average IQ while 10 percent were above average.’
How can you state this falsehood when I just showed that the study did no such thing. It showed, if you do the math, that the average IQ of 100% of the Indian students was 112.55, which is certainly at least 2SD’s above that of an “average” Indian student (whose IQ is between 80 and 85).
“Though for all jobs, IQ doesn’t really matter.” I do wish you would be clearer in your statements so you don’t keep having to “clean them up”. Of COURSE IQ matters.
Here is a study showing IQ spans for various professions. At the high end are college professors and medical personnel (starting around !Q 110).
Click to access 98-07.pdf
Can an average Indian student (IQ 80-85) become a doctor? I don’t think so. Not even if he is really, REALLY motivated.
Those who persist with the silly IQ denialism need to go read Gottfredson (see page 117 particularly)
Click to access 1997whygmatters.pdf
You’re assuming a normal distribution. Psychological traits aren’t normally distributed (O’Boyle and Aguinis, 2012).
That aside, I’ll accept that. How did you ascertain the exact individual IQs from the range in table 3?
They write on page 277:
Most of the medical students (169, 56.3%) taken one year drop for medical entrance preparation. These students had average IQ (78) above average IQ (85). 33 (11%) students needed more than 2 years for medical entrance exam preparation, 30 (90.9%) of them had average and below average IQ (Table 4).
And their explanation on pg 279:
The students with higher IQ belong to upper socioeconomic class and their parents were well educated. The educational qualification of mothers of these students was found to be higher than rest of the students. It signifies that the family environment, childhood nutrition and illnesses and schooling may have determinative role in the adult intelligence.
Also on pg 279:
Most of the medical students had average IQ or above average IQ. Only very few students had extraordinary /genius or gifted intelligence. Students with poor IQ/mentally challenged were not able to clear medical entrance. Students with higher IQ and above average IQ needed lesser time for medical entrance and even during MBBS course for class and routine studies.
Did you read Richardson and Norgate (2015)? The correlations with job performance are much lower than the adjusted correlations are. Within jobs work sample scores predict job performance better than IQ. That’s straight from the Hunter and Schmidt studies.
I’m not “denying IQ”. I’m questioning the relationship within jobs to IQ. I am entertaining the idea that IQ tests are proxies for social class. We can discuss this elsewhere on this blog though.
Further, the Indian study rallies against the use of IQ tests for medical school screening. I’ve shown that academic achievement scores predict academic success better than IQ (see McManus et al, 2003 and see McManus et al 2013 that IQ tests don’t predict promotion to senior doctor).
One more thing, my quote that “intelligence is irrelevant to becoming a doctor” was meant senior doctor, as I clarified at the very end of the piece.
If you want to discuss IQ tests, social class, IQ test construct validity and how IQ tests are constructed overall then leave a comment here. I’m already discussing this with someone else. g is not a thing. It is not physiological. What do IQ tests test? If general intelligence (whatever that is) is physiological, then what physiological process in the body would it be compared to? Stroke volume? Blood pressure? White blood cell count? Red blood cell count?
Still waiting on an individual theory of intelligence differences/g. Deary and Jensen say there is no theory for individual differences in intelligence, nor a theory for why individuals differ in g (whatever that is). That’s a huge problem. Deary even says there is no “grown-up” theory of individual intelligence differences.
I’ll be waiting forever for that.
(There is a pdf available here of the Indian doctor-IQ study.)
Intelligence quotient analysis and its association with academic performance of medical students.
IQ outperforms, hard work, creativity and free markets when predicting overall development in the OECD nations
This was a mischaracterization of the academic evidence, at best. First off, one must understand a.) the basic pathogenesis and functional understanding of intelligence, b.) IQ (g) and its replicated content validity, and c.) why it has functional importance regarding job performance.
IQ is just a rudimentary, non-biological measure of cognitive ability. It is akin to a pulmonary function test for a respiratory condition without having access to imaging, blood work, and bronchoscopy. There are over twenty serious pulmonary conditions that exhibit the same symptoms and will show reduced PEF. One can not differentiate COPD from IPF from just a pulmonary function test; however, both are VITAL in understanding “lung function.”
IQ measures a general cognitive ability. Most of these mechanisms are subconscious and have a biological pathogenesis. For instance, one can be taught to read and write, they cannot, however, be taught decoding ability, processing speed, and hypothetical abstraction. In math, there are many complex underlying mechanisms at play which clearly separate a rocket scientist from a carpenter. To say that IQ does not matter — or to dilute its validity — particularly for complex jobs such as medicine, which requires advanced processing speed, crystallized intelligence, and spatial intelligence, is absurd. So, in essence, the basic pathogenesis of IQ is a multitude of complex mental processes which underly many functional skills.
One interesting emergence only recently is the intersection between IQ and Schizophrenia. In the past, experts believed the disease lowered IQ, itself. Now, recent evidence is showing that what we call IQ — what they would call underlying mental processes — actually protects the brain. How? Because there are incredibly complex processes, particularly regarding the dopamine pathways, which intersect with genetic cognitive ability — from childhood.
Second, IQ has proven content validity. Only individuals without knowledge of Jenson’s work could dissent and reach such a fallacious conclusion. Remember, Spearman’s psychometric theories have never been statistically invalidated, and it was Arthur Jensen who perfected many of the original assumptions. Moreover, IQ has been replicated — many, many times over — and has wide acceptance by the APA — which even talks about it on their website.
Not even Taleb, despite his sheer brilliance but dogmatic inferiority-complex, have disproven IQ.
If we therefore accept the aforementioned then, regardless of social science research — which will always be slightly rudimentary — we must accept that cognitive ability, otherwise known as IQ (g) plays an independent role in job performance. The same exact conclusion both Murray and Gottfredson arrived at decades ago. Furthermore, perhaps your biggest mistake — besides cherry-picking the literature — was creating a tripartite dichotomy. Remember, as Dr. House always states “it is always one thing.” Cognitive ability AND trait conscientious are necessary for complex jobs. However, the latter only accounts for about ten percent of difference. The former, at least 40% — despite Richardson’s study.
One can work hard but, with an IQ of 95: will never be doctor. A lazy genius will never be, either, but not because of cognitive deficiency.
Another interesting topic is the consistent correlation between intelligence and brain size. Key word: correlation. There are “most likely” over 20-30 differing mental functions — neural connectivity, neurons, glucose, dopamine pathways, neurotransmitters, etc — which all play some basic and adaptive role in what we consider to be: IQ.