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rebellionkid comments on Why Are Individual IQ Differences OK? - Less Wrong
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First, I want to say this: I have no idea whether his claim that Africans got a lower IQ score on the test in question is true or false. I hope it is false. There's a possible explanation that is totally in support of the Africans, EVEN if the claim was true. Here it is:
IQ tests are culturally biased. If the test asks "How do you use a teacup?" a British person will be likely to know the answer - a lot of them use teacups daily. Do Africans use teacups every day? Maybe they'll bomb on the teacup question because they drink their tea from bowls as with Japanese matcha tea, or from gourds as with yerba mate tea. If you ask them "Is a rattlesnake dangerous?" that question is irrelevant to them. They have boa constrictors, but not rattlesnakes.
There are tests that are designed to prevent these differences from influencing your score. They're called "culture fair tests". Nobody here has specified whether a culture fair test was used (I searched the page).
I think this is the most interesting sentence in the whole discussion.
Let's be clear. Racial groupings are really very significant pieces of evidence. There's huge amounts of genetics that correlates, huge amounts of culture that correlates, huge amounts of wider environment that correlates. It would be frankly astonishing if things like IQ, reaction time, hight, life expectancy, and rates of disease didn't also correlate.
So, we ought to expect to see a correlation, and in fact a whole bunch of studies say we do. ... And then those studies are put under far more than average pressure. See people below wanting to dismiss Raven's Progressive Matrices as culturally biased. Why on earth do we want there to be no such correlation with IQ.
We're very happy to say there's a correlation between race and hight, between race and life expectancy, between race and disease, between race and income. Why not race and IQ? Why do we want that to be false?
Well, there's a correlation between race and height, too, no doubt, but such correlation is utterly insignificant comparing to variance within either race - you don't say whites are taller or blacks are taller, there's very short black populations and very tall ones, and ditto for the whites whose variance is smaller.
The quantitative differences make a qualitative difference here.
Racists believe the correlation to be of greater significance than that of correlation between the height and intelligence. Based on fairly poor evidence - Raven's matrices are not this culture fair, they're culture fair in the sense that you can test British, Germans, French, Russian, and Chinese and Japanese with it, not in the sense that you can go and test some tribe that doesn't do much arithmetic nor is exposed to similar visual stimuli.
By the way given the diversity of blacks it would be utterly surprising if there is not a single ethnicity there with an average IQ greater than 100, as well as IQ with greater or smaller variance. (I would expect blacks to have larger variance than whites because they're plain more diverse, and mixed to have greater variance still)
Then the "rational" racists also object to use or even the existence of correlation between such racism and intelligence, conscientiousness, education, and other factors.
Notice I said nothing at all about racism or our policy responses to race. Of course intra-group variation is more important, that's obvious and applies to height too. This much is well known and irrelevant to my point.
The thing I'm interested here is why it's commonly accepted that there ought (in a strong moral sense) to be no correlation. Not our response to the actual existence of that correlation.
I am not aware of any test of pattern recognition that is more culture fair than Raven's, but would love to hear of one if you're familiar with one, and I would be rightfully suspicious of the intellectual capabilities of a tribe that has not invented arithmetic.
I'm not aware of many ethnicity-level studies; I think the best we have are nationality-level studies. The highest country mean in all of Africa that I'm aware of is Morocco, with 85.
It's an interesting and very common form of an entirely irrational argument. (Hypothetical) absence of a better test in no way implies that it is a good enough test for a select purpose. Especially when no one really tried to quantify the error you might get.
I said, "doesn't do much arithmetic". You can look at the whites 1000 or 2000 years ago and vast majority don't do much arithmetic. "Haven't invented arithmetic" is your invention.
I prefer quantitative arguments to qualitative arguments; relatedly, I prefer certainty as a number to certainty as a word. I think it's better to make the most of mediocre data (and figure out which additional data is highest EV) than to throw out the best data available.
It is not true that people haven't tried to quantify the error they might get; this is actually a major concern of psychometricians. They've figured out several ways that a test can go wrong, and have come up with quantitative measures on how much those seem to have happened. For example, a problem with WWI-era IQ tests was that the modal number of correct questions was 0, which suggests that a large number of test-takers did not understand the instructions, which dropped the uncorrected mean significantly. Now they look for this problem.
For example, here's a paper about Raven's in Africa, which goes through the various ways that Raven's could underestimate African intelligence. It's full of quantative statements like "the correlation with other intellectual tests is generally about .6 in Western studies, but is .33 in African studies, suggesting it is less g-loaded for Africans."*
If you wanted, you could figure out what an individual Raven's score of 80 implies for any other cognitive test in Westerners and Africans respectively. Like any Bayesian exercise, this relies pretty heavily on the priors you choose: if you assume the score is accurate but not precise, then you have a mean centered on 80 but a difference variance for the two groups, with a larger African variance because your test is less precise. If you assume both groups have the Western mean, then the regression to the mean (i.e. upwards) is higher for the African than the Westerner, again because the test was less precise.
*I should point out that there are other, competing interpretations of this finding, and it seems that the correlation is lower for the more rural and less educated, suggesting the left half of Fig 4 is due to culture. But from the studies on the right half of Fig 4, we would end up with an estimate for African intelligence given Western culture that's about 80-85, which is a bit lower than African American intelligence.
I was thinking of anumeric tribes, which are rare enough that we're not quite sure whether or not they exist. But many tribes seem at least partially anumeric, and I would be surprised if that were not predictive of the mean IQ of people currently in the tribe (setting aside the question of 'genetic IQ capability').
That most Romans did not do much arithmetic over the course of their lives doesn't say all that much about their ability to do arithmetic or their general intellectual capability; most modern Americans don't do much arithmetic (and, actually, they probably do less because they have more machines to do it for them).
Culture and environment are not race. Therefore, if you're studying race, those influences should be taken out of your scientific experiment. It's extremely difficult to remove things like culture and environment from a study on IQ. The fact that so much is correlated with it doesn't mean the results of studies intended to determine racial differences are significant so much as it means they're a tangled mess of cause and effect which we likely haven't sorted out adequately.
A. We don't want black people to suffer needlessly.
B. We don't want to encourage ourselves and others to be prejudiced against people when, regardless of what the average African's IQ is, it is still both logically incorrect (hasty generalization) and ethically wrong to prejudge individual Africans. However, knowing how humans behave, we figure that if people believe Africans have lower IQs, that will result in an increase in prejudice.
Actually, I bet some people are not happy saying that there are correlations there. This is one of those notions you might want to double check.
So what you're saying is that it's ethically wrong to use Bayesian reasoning.
Is it inconceivable that this could ever be the case?
It is dangerous to be half a rationalist. This applies to groups as well as individuals. No matter how good your process for arriving at beliefs, it is indeed unethical to go around spreading those beliefs to people that will predictably misunderstand and misuse them.
Funny how the only people to make that argument tend to be people who don't want to believe the beliefs in question, but have out of ways to ignore the evidence.
On a less meta level: what kind of "misunderstand and misuse" do you think is going to "predictably" happen.
In the interest of clarity: I am not at all sure how to proceed in this particular case. History makes me wary of departing from the current Schelling point of assuming everybody is equal, but that's not my point.
I am saying that a course of action based on Bayesian reasoning has no special immunity to being ethically wrong, and it is those actual results that are worth worrying about, not merely the epistemology.
I, for one, do believe that the average African has lower IQ than the average European but don't go around telling that to the wrong people.
Underestimating how much the evidence race provides about an individual's IQ can be screened off by other evidence about the individual, due to the confirmation bias and similar.
It is almost always bad Bayes, or any other kind of reasoning, to make judgements about individuals based on group characeristics, since there is almost always information about them as individuals available which is almost always more reliable.
Group level information is still useful for shrinkage of estimates and correcting for the always-present unreliability in individual estimates; see for example the long conversation between me and Vaniver on LW somewhere where we work through how you would shrink males and females' SAT scores based on the College Board's published reliability numbers.
And E(X's deserved SAT score|X's measured SAT score; X is male) - E(X's deserved SAT score|X's measured SAT score; X is female) was, like, four points? I still think people's System 1 are likely to overestimate this difference if they know about the correlation more than underestimate it if they don't.
A 4 point adjustment (or more) across all candidates based solely on 1 binary variable (gender) and a trivial centuries-old bit of statistical reasoning seems like a fairly impressive output, and likely to make a difference on the margin for thousands of applications out of the millions sent each year.
And your evidence for this is...?
For applicants scoring 800 on a hypothetical normally distributed math SAT, yep. For normally distributed tests, shrinkage is linear based on the difference between the group mean and the measured mean, and so it's smaller for less extreme scores.
(For some reason, I'm having difficulty finding the link to the actual conversation; I think Google search is not going into deep comment threads, and the search function is based off the site, rather than just a database of my comments. Anyone remember helpful keywords further upthread to get a link to the actual conversation?)
Saying "we shouldn't explicitly calculate something because some people might implicitly calculate that thing incorrectly" sounds to me like going in the exact wrong direction.
Here is Wei Dai's tool for searching LW comments.
If you intend to use an African prejudgment heuristic like 1 (below) rather than reacting as if you've done an equation that takes into account other relevant data like 2 (below), then I think your probability equation needs an upgrade.
1) African prejudgment heuristic: "The IQ test(s) said African's IQs are lower than those of whites, therefore this specific African individual is likely to be relatively stupid compared to my white friends."
2) Reasoning that Takes Relevant Data Into Account: "The IQ test(s) said African's IQs are lower than those of whites. However, there are known flaws with IQ tests such as cultural bias, so that figure might be wrong. Most published research findings are false (PLOS Medicine), so I should apply healthy skepticism to all the research I read. This is not likely to be an accurate piece of data to use as a Bayesian prior. Once I've decided on a prior to use, I should then adjust for other relevant data (things I know about the specific individual).
Then, if one wants to behave rationally after one has decided what to believe, I think one must continue by thinking something like this:
"Considering things like...
A. ...the fact my prior is likely to be inaccurate (there isn't an accurate one for this subject as far as I'm aware)...
B. ...the fact that even if the IQ study is correct and the IQ test it used was accurate, there's a decent chance (25%) that this specific individual has an IQ above the African average - meaning I need to avoid the logical fallacy called hasty generalization...
C. ...the risk of lost utility via damaging this individual's reputation, emotional health or opportunities for success by pre-judging them...
D. ...the risk that this makes for bad social signaling and witnesses may retaliate against me with one or more forms of social rejection if I pre-emptively treat an African like an idiot...
...do I really want to treat this person as if they are less intelligent?"
I think you may have reacted to my "I hope it is false." statement or my "it's ethically wrong to prejudge individual Africans" statement - but that shouldn't matter to your probability calculation. What should matter is to get an accurate idea of reality. Along with saying other things, I also provided other factors which are relevant, as credible sources can confirm. If one wants to be a good Bayesian probabilist, after one specifies some prior probability, one must then update it in the light of new, relevant data. [1] This situation where you focused on one part of my comment and ignored the rest reminds me of those math problems where there's an irrelevant statement thrown in just to distract you. I of course did not intend to distract you, but since you seem to think that Bayesian reasoning in this case means ignoring all the other data I presented, it appears that you have skipped the parts of the process where you ensure an accurate prior and update your prior with new, relevant data.
Life is really, really complicated. I doubt it's ever wise to just grab a prior and run with it and I certainly hope that you do not reason this way.
All of that looks like rationalization of a pre-determined belief.
No it doesn't. The conclusion supported is far too close to the 'middle ground' on the issue to readily pattern match to rationalization and seems to be a description of considered reasoning from plausibly held premises. The 'rationalisation' and 'pre-determined belief' charges could be credibly made in response to many of the comments in this thread but doesn't apply to the grandparent.
NOTE: I don't entirely agree with with either Epiphany's position or Eugine's position. In particular Epiphany seems a little too disillusioned with research while Eugine has somewhat too much passion on the race/IQ political correctness subject to keep his claims balanced enough that I could support them despite agreeing that there are almost certainly IQ differences between groups selected by just about any significant feature---not that this seems like an especially useful thing to place emphasis on. I seem to recall some credible claims about higher average mathematical intelligence in Ashkenazi Jews for example.
Regardless of whether I agree with the position being argued with, the parent is making what seems to me to be a false accusation and one of a kind that derails the flow of discourse.
Respectfully disagree, though we may be focusing on different parts. It worries me that your analysis seems to focus on the conclusion drawn rather than the procedures followed.
Consider this bit of the great-grandparent:
This looks like pure rationalization to me, with many inaccuracies and irrelevancies, all of which support the intended conclusion. (An unbiased sloppy thinker should be expected to make mistakes in both directions simultaneously; when the mistakes all point one way it suggests bias.) The most egregious irrelevance is the attempt to discredit one of the most replicated findings in social science with a study that showed that prominently promoted recent research often fails to replicate. The last sentence is bizarre by its addition- would someone using race as Bayesian evidence not update on other information? (The later reference on Bayesian updating is similarly bizarre.)
The rest of the great-grandparent discusses how, even if we had an estimate, we should be careful how we use that estimate. Of course--who would argue against using estimates carefully?--but irrelevant to the question of whether or not it is ethical to use Bayesian reasoning.
This reads like a classic case of motivated cognition. You don't want to believe the conclusion; therefore, you selectively look for potential flaws then declare that there's still a chance. The reason I believe the connection between race and intelligence is not just because of the tests but because more or less every relevant aspect of reality (e.g., the statistic on race and crime, the nearly complete lack of blacks in intelligence intensive fields, e.g., math, programing, the state of majority black countries) looks the way one would expect it to look if the connection existed.
Who is claiming otherwise?
Yes there is. You just don't want to believe it exists.
Actually the chance of this particular black being above the African average is 50% (more if I condition on the fact that he is in the USA). The probability that he is above the white average is significantly less. The probability that he is above some high cutoff is can be even lower.
This is a general argument against using evidence of any kind.
This is potentially a problem, although here the problem is arguably with the witnesses behaving irrationally and/or participating in out of control signaling arms races than with the strategy itself.
Did you stop to make distinction between me being influenced by motivated cognition and alternate explanations like:
Me seeing significant flaws in data that would otherwise support your conclusion. Part of this may be that I've spent a significant amount of time reading about IQ and giftedness and I have learned that there are a lot of pitfalls to doing IQ related research.
Me simply being unaware of relevant data. (This might be the case in the event that the people who supplied my data were influenced by motivated cognition or confirmation bias.)
You seeing motivated cognition in my words because of being influenced by motivated cognition yourself?
There is an alternate explanation for those which does not have the same issues that IQ tests and studies have: The effects of slavery and prejudice. We are certain that slavery and prejudice has influenced them, and that it has existed for a long time. To know this, one must only look at the KKK or investigate the history of black enslavement. Imagine a third world country. Imagine that an equal proportion of those inhabitants are removed and used as slaves. Imagine an equal proportion of them dying. Imagine that they're freed, but all of them - not some but all - are freed into a situation of extreme poverty where they don't even own a home or have the ability to read. Many still aren't being taught to read. Consider also that even though there have been advances in medicine, poverty means you can't afford health insurance or medical treatments. Don't think that disability and chronic illness are uncommon - they're not. Not even in America. They're probably especially common for the poor. Don't think that severe worker abuse ended with slavery, either - do some research on sweatshops in America sometime. Now take into account the effects of stress, and the human element - how those effects can compound into things like mental illnesses and drug addictions. Would you predict that the majority of these people who started out with literally nothing and without even the education to read would manage to avoid pitfalls like disability, mental illness, drug addiction and sweatshops and carve an opportunity to excel out of poverty and ignorance over the course of 150 years? I would not expect that. I would expect most of them to have fared poorly.
I don't see a good way to tell the difference between a low IQ score due to actually being less intelligent versus a low IQ score due to nurture-related reasons such as the following:
If you want to attribute the IQ scores to race, not poverty or circumstances, then there needs to be a good way to distinguish between nurture and nature as a cause for low IQ scores. Do you have one?
If it's true I want to believe it. However, it's hard to believe it exists without a citation. Do you have one?
I respect you more for being able to say something that supports my view better than it does yours. +1 karma for that. I still think the number is 25%, however I do not view this as a key point in our disagreement, so I will leave it at that.
You appear to have taken that statement as an argument regarding what to believe. It was not. I deliberately put that part after the section where I was discussing deciding what to believe, and put it under "if one wants to behave rationally".
In Africa? It so happens that the world is much bigger than the USA and the people in sub-Saharan Africa test for IQ pretty much the same as African-Americans.
Sure, you can control for wealth/economic status. Or you can go and test poor peasants in China and poor peasants in Africa. You seem to think that this is a white-vs-black US problem. It's not. The highest-average-IQ large group of people is East Asians, like Han Chinese -- not Caucasian whites.
I am curious -- how do you figure out that in a distribution close to normal only 25% are higher than the mean?
Actually much of sub-Saharan Africa has average IQ around 70, whereas African-Americans average around 85.
Yeah. I suspect there are two reasons for that. First, malnutrition as a child can drive your IQ down and malnutrition is much more common in sub-Saharan Africa. And second, many African-Americans have some white ancestors. Look at Obama, for example -- he self-identifies as African-American though only half his genes come from Africans.
If your point is that it's not clear to what extent the difference in intelligence is due to nature or nurture, I agree but would like to point out that for many applications it doesn't matter.
"X have a lower IQ on average."
You can choose "People of African descent" or you can choose "People from poor backgrounds" or "People with serious health conditions" or "People with drug addictions" or any number of other things.
When attempting to determine how best to help a school in a black ghetto that is failing, and you're choosing between spending money on remedial courses or on a school nutrition program, you will most certainly benefit from having this knowledge.
Conversely, I can't think of any applications for which tying IQ to race is useful. Would you name three examples?
Also, I'm still interested in seeing the source that you believe is an accurate prior regarding race and IQ. Do you happen to have that information available?
The Bell Curve book is a standard source. Otherwise a quick look at Wikipedia provides this:
You might be in a situation where you need to decide how to allocate money to help a black school or a white school. If white people have higher IQs, and if money is worse at improving the performance of students who do poorly because of IQ than it is at improving the performance of students who do poorly for other reasons, then you should allocate the money to the white school.
You might be in a situation where you need to hire a white person or a black person and have no information about their IQs, but you would prefer an employee with a higher IQ. You then should hire the white person.
Of course, this is exactly why using IQ this way is a bad idea.
If the results of the racial IQ studies are true, then that is very important because it disproves the doctrine of ethnic cognitive equality. Many people, especially in America, have this idea that all ethnic groups must have exactly equal average cognitive ability, and that if one or more ethnic groups perform below average on a test of aptitude, that is taken as strong evidence that the test is invalid and racially biased and thus cannot be used.
For this reason, many aptitude tests are severely restricted in their use since they are considered racist. This in turn would have a negative economic impact if these tests are actually valid, since employers and colleges are forced to use other, less effective means to vet candidates.
Well, seeing an unknown man approaching you at night, granted this is more about criminality than IQ but the correlation is the same.
Also thinking about whether affirmative action and the desperate impact doctrine are reasonable ideas.
As the saying goes, "Life is an IQ test." The predictive ability of IQ on income (and most other statistics of interest) is very similar for each race, which suggests that differences in measured IQ scores map onto differences in life outcomes. To the extent that a medical condition makes someone test poorly, it generally also makes them live poorly. (There are a handful of prominent exceptions to this- like dyslexia- which don't significantly impact the main point.)
Now, where those IQ differences come from in the first place is an interesting question. Many people have looked at it, and the consensus answer for individual IQ differences is "somewhere between 50% and 80% of it is genetic," and the extrapolation from that to group IQ differences is somewhat controversial but seems straightforward to me. A perhaps more interesting question is "what knobs do we have to adjust those IQ differences?"
Here's Jason Richwine explaining that all serious scientists have agreed on the basics of IQ for decades, and the media is completely mistaken on the state of reality and scientific consensus.
It seems pretty relevant to me, because it looks like basic statistical innumeracy on your part, unless you think the IQ distribution of African Americans is tremendously skewed such that the mean intelligence is the 75th percentile of intelligence, rather than the 50th percentile like it would be in a symmetric distribution. (Or you think that the African average is higher than the African American average, which is very much not the case.)
As a stand-alone statement, I would probably leave this alone. But as a response to "What about nurture", the first thing that comes to mind is:
Has Vaniver adequately corrected for the just world fallacy?
Ok, that's interesting, but it does nothing to rule out nurture factors that would impact both IQ and income.
I agree that IQ is mostly genetic and that IQ does seem to correlate with a lot of factors. I'm not saying IQ does not exist. What I am saying is that, specifically when it comes to black people, there are other factors that are definitely influencing performance and IQ scores. Therefore I reject claims about IQ and race that haven't controlled for known factors.
Actually, when I read that section (it starts with "What scholars"), I parsed it like this:
Jason explicitly says that there's a scientific consensus on many issues that seem controversial to journalists.
Jason states that virtually all psychologists (not scientists) believe there is a general mental ability factor (That he's not saying is specifically connected to race).
Then, without qualifying these statements with anything along the lines of "most x believe", he states: "In terms of group differences, people of northeast Asian descent have higher average IQ scores than people of European lineage, who in turn have higher average scores than people of sub-Saharan African descent."
I will not assume that this sequence of claims means that the group differences statement is also something scientists have a consensus about. If I did, that would be a non-sequitur.
Also, below that, he writes:
"It is possible that genetic factors could influence IQ differences among ethnic groups, but many scientists are withholding judgment until DNA studies are able to link specific gene combinations with IQ."
This is where I stop reading the article because it is clear to me that it does not say "there's a scientific consensus that there's a link between race and IQ". If you have a credible source for that claim, I'll be curious about it. No more Politico articles please.
It might or might not have been an error. In any case, I'm not going to go digging for that right now because I still think knowing the percentage is irrelevant to the current point. Whether the figure is 50% or 25%, it is still true that a significant proportion of people will have an IQ above average and therefore it would be hasty generalization to assume that a person of a certain group was an idiot. That is one way in which the exact number is irrelevant. However, that point about hasty generalization is much more irrelevant at this particular moment because we haven't even decided on a prior, let alone have we got a decent posterior - so the step where we have a concern about making a hasty generalization based on our probabilities should be in this disagreement's future. If it becomes relevant, I will dig around, but not right now.
It's not clear to me why you would be interested in nurture factors. There are two things going on here: the ability of IQ to measure intelligence, and the historical causes of intelligence.
With the exception of disorders that prevent people from testing well without significantly impacting life outcomes, the historical causes of intelligence don't appear to have much to do with the ability of IQ to measure intelligence. A nurture factor (like, for example, being breastfed as a child or being struck on the head) actually alters someone's intelligence, and their intelligence influences both their test scores and their income.
Again, this looks like it's mixing up the historical causes and the predictive ability. If the predictive ability is the same independent of race (it is), then it doesn't matter why the racial IQ averages are the way they are. What we would need to show to discount IQ measurements is that the IQ measurements are not as predictive for members of one race than another.
As an example of a real bias like this, girls tend to get better grades than standardized test scores alone would predict. In order to get an accurate estimate of what a girl's grades would be from her standardized test scores, you need to adjust upwards because she's a girl. Symmetrically, boys score better than one would expect from their grades, and so when predicting scores one needs to adjust upwards. When moving in the opposite direction, one would need to adjust downwards; a girl's grades overestimate her standardized test scores. But note that this doesn't mean we throw out the data- it's still predictive! We just adjust it the correct quantitative amount.
Now, do we know the historical causes of that effect? I'm not familiar with that field, but it seems like there are lots of plausible theories that probably have support. Even without knowing the causes, though, we can use our estimates of the size of the effect in order to predict more accurately.
What would you call a scientist who studies intelligence? (I suppose I should also make clear that by "serious" I mean a scientist speaking confidently in their field of expertise.)
One does not say "most scientists believe that hydrogen has one proton," one says "hydrogen has one proton."
Here's the APA report he references. The group means section starts on page 16.
In general, though, asking for citations like this is really frustrating, because it doesn't seem like the true rejection. The linked Richwine article referenced more serious sources that you could find if interested, and even if you didn't notice that Googling "racial IQ averages" leads to this as the fourth hit, and if sufficiently motivated you could find the paper that journalist was writing about, and so on.
But if you're not curious enough to seek out this information, and you don't seem to have updated on the other information I've provided, what reason do I have to expect that the difference between my position and your position is that I have citations, and as soon as I share them you'll adopt my position?
Sure. When you think in distributions, an estimate generally comes with both a mode and a precision (or, relatedly, the standard deviation). Knowing someone is African American gives you an estimate with a mode of 85 and standard deviation of 15, which has a non-trivial but small chance of being over 120. Knowing someone got a 120 on a recent IQ test gives you an estimate with a mode slightly south of 120 and a standard deviation of probably 2-5, depending on the precision of the test.
That's a saying? Are there also sayings "Life is a test of height.", "Life is a test of immune system efficiency" and "Life is a test of facial symmetry"? We may as well round out the set. Anything of comparable test significance that I missed? Oh! "Life is a test of breast perkiness" and "Life is a test of capacity for situation-appropriate violence."
(I actually agree with the point of the rest of the paragraph.)
Those may be qualitatively similar but I would suggest they are quantitatively different. I would be surprised if facial symmetry did not correlate with income, health, social status, and so on, but I would expect the correlation to be much lower than the correlation with IQ. The saying means that most metrics of life success are moderately highly g-loaded, and so it makes sense that IQ correlates positively with basically everything good.
EDIT: sorry, misunderstood your comment.