Finishing up with our discussion, (in response to a reader’s question):

Why are people snobs about intelligence? Is math ability better than verbal? Do people only care about intelligence in the context of making money?

Now, this is the point in the conversation where somebody tends to say something like, “My cousin / little sister /uncle is retarded, but they are still a beautiful, wonderful person and I love them as much as everyone else, and therefore it is mean to say that smart people are higher status than dumb people.”

It is good that you love your family. You should love your family. I am sure your relatives are lovely people, and you enjoy their company, and would be worse off without them.

But by the same token, I am grateful for the fact that I have never had polio, smallpox, or Ebola. I am thankful that I did not die in childbirth (my own or my childrens’.) I am thankful for life-saving surgeries, medications, and mass-vaccination campaigns that have massively reduced the quantity of human suffering, and I happily praise the doctors and scientists who made all of this possible.

That is why doctors and scientists are higher status than dumb people, and why math-smart people (who tend to end up in science) believe that they should have more status than verbal-smart people.

But on to #3--what is this “intelligence” and “money” connection? (And why does our questioner think it is so bad?)

The obvious answer is no, people don’t only care about intelligence in the context of making money. People also care about enjoying music and reading good books and having fun with their friends, having pleasant conversations and not dying of cancer.

But people are practical creatures, and their first priority is making sure that they and their children will eat tomorrow.

In a purely meritocratic society, more intelligent people will tend to end up in professions that require more intellect and more years of training, which will in turn allow them to demand higher wages. (So will people with rare physical talents, like athleticism and musical ability.) Unintelligent people, by contrast, will end up in the jobs that require the least thought and least training, where they will soon be replaced by robots.

The incentive to pay your doctor more than your trash collector is obvious.

The truly bright and creative, of course, will go beyond merely being employed and actually start companies, invent products/processes, and generally reshape the world around them, all of which results in making even more money.

The truly dull, by contrast, even when they can get jobs, tend to be impulsive and bad at planning, which results in the loss of what little money they have.

We do not live in a purely meritocratic society. No one does. We make efforts to that end, though, which is why public schools exist and employers are officially not supposed to consider things like race and gender when hiring people. Which means that our society is pretty close to meritocratic.

And in fact, the correlation between IQ and wealth/income is remarkably robust:

It even holds internationally:

There are a few outliers–the gulf oil states are far richer than their IQs would predict, due to oil; China is poorer than its IQ predicts, which may be due to the lingering effects of communism or due to some quirk in the nature of Chinese intelligence (either way, I expect a very China-dominant future)–but otherwise, IQ predicts average per cap GDP quite well.

Here people tend to bring up a few common objections:

1. I know a guy who is smart but poor, and a guy who is dumb but rich! Two anecdotes are totally sufficient to completely disprove a general trend calculated from millions of data points.

Yes, obviously some really smart people have no desire to go into high-paying fields, and devote their lives to art, music, volunteering with the poor, raising children, or just chilling with their friends. Some smart people have health problems, are unfairly discriminated against, live in areas with few jobs, or are otherwise unable to reach their potentials. Some dumb people luck into wealth or a high-paying job.

It would be a strange world indeed if IQ were absolute destiny.

But the existence of outliers does not negate the overall trends–smarter people tend to get jobs in higher-paying fields and manage their money more effectively; dumb people tend to get jobs in lower-paying fields and manage their money ineffectively.

2. Maybe everyone is equally smart, but just expresses it in different ways. (Corollary form: IQ is just a measure of how good you are at taking IQ tests.)

Either we mean something when we say “intelligence,” or we do not. If we want to define “intelligence” so that everyone is equally smart, then yes, everyone is equally smart. If we want to know if some people are better than others at doing math, then we find that some people are better than others at doing math. Are some people better than others at reading? Yes. Are some people better than others at football? Yes.

If you transported me tomorrow to a hunter-gatherer community, and they gave me a test of the skills necessary for survival there, I’d flunk (and die.) They’d conclude that I was an idiot who couldn’t gather her way out of a paper bag.

Very well, then.

But neither of us lives in a hunter-gatherer society, nor do we particularly care about the skills necessary to survive in one. If I want to know the kinds of intelligence that are necessary for success in industrial societies–the kind of success that may have led to the existence of industrial societies–then you’re looking at normal old “intelligence” as people conventionally use the term, measured by IQ scores, the SAT, vague impressions, or report cards.

3. “You’ve got causality backwards–people with money send their kids to expensive prep schools, which results in them learning more, which results in higher IQ scores. These “smart” kids then use family connections/prestige to land good jobs, resulting in higher wealth.”

Luckily for us, we have adoption studies.

Quoting Jayman:

As this shows, the heritability of IQ and of behavioral traits is consistently high, reaching into the 0.8-0.9+ range. This means, out of a group of people, at least 80-90% of the overall differences between them (known as the “variance” in statistical parlance) can be attributed to genetic differences between them. This chart shows that this becomes most evident in adulthood, when genes have been given a chance to fully express themselves. I have summed this up in a neat set of rules: Heredity: 70-80% Shared environment: 0% Something else [random chance]: 30-20%

In other words, adopted kids end up with the IQ scores you’d predict from looking at their biological parents, not their legal parents. Baring extremes of poverty or abuse, the way your parents raise you–including the quality of the schools you attend–has very little long-term effect on IQ.

On a related note, massively increased school expenditures since the ’80s has done very little to test scores:

Jayman continues:

IQ doesn’t lend itself to much environmental manipulation – indeed, interventions that attempt to boost IQ have all met with failure. As well, IQ remains predictive even when measured in youth. It is predictive even when one controls for things like socioeconomic status (say during childhood). Indeed, the best control for this, looking at different siblings within a family, finds that IQ is predictive of real world outcomes between siblings – the sibling with the higher IQ tends to do better. These are in addition to the fact that there are visible physiological correlates with IQ, such as head and brain size, as well various anatomical features of the brain, such as cortical thickness (Pietschnig et al, 2014, Shaw et al, 2006, Menary et al, 2013, Karama, Deary, et al, 2011). Indeed, a recent research team found that they were able to accurately gauge IQ from brain MRI imagery alone (correlation of 0.72 between prediction based on imagery and test-measured IQ – Wang et al, 2015 – see also Steve Hsu, Information Processing: IQ prediction from structural MRI).

4. Your map is racist.

That’s the million dollar objection, isn’t it?

Everybody wants to know why some groups or countries out perform other groups or countries, but no one likes to be told that they–or a group that they belong to–are less intelligent than others. No one wants to be in the red; everyone wants to blame their troubles on someone else.

Thus a great deal of debate; some people want to prove that the wealth and poverty of nations depends on IQ, and some people want to prove that it does not. No matter your personal opinions on the matter, it’s pretty hard to have a discussions about IQ without the debate resurfacing.

Incidentally:

Now, I fully believe that rich people enroll their kids expensive test-prep classes, which result in small increases in SAT scores over students who’ve never seen the test before (an effect that wears off once classes are over.) It may also be that people from countries where schools barely exist look at a test and have no idea what you want them to do with it, regardless of intelligence. But if parental income were the entire story, rich whites, blacks, Hispanics, and Asians ought to all get similar SAT scores, (with the exception of verbal scores for ESL-students,) and poor whites, blacks, Hispanics, and Asians ought to all get similar, lower scores. Instead, the children of wealthy Black parents have worse SAT scores than the children of poor whites and Asians. (Except Asian verbal scores, which are pretty bad at the low end–probably an ESL-artifact.)

Regardless, a certain kind of intelligence appears to be useful for building certain kinds of societies.

Conclusion:

Yes, there are lots of reasons to value intelligence, like making art and enjoying a good book. And there are many lifestyles that people enjoy that do not require making lots of money, nor do they have much to do with capitalism. But there exists, nonetheless, a fairly reliable correlation–at the group level–between average IQ and income/wealth/development level. Most people don’t care about this because they want to exploit each other and destroy the environment, but because they want to be well-fed, healthy, and happy.