Intelligence & Inheritance

3,340 words / 20:55

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Audio Version: To listen in a player, click here ^[2]. To download the mp3, right-click here ^[2] and choose “save target or link as.”

Now that I’ve given a cursory definition and defense of “race,” ^[3] it’s time to move on to IQ. This essay will address IQ separately, before synthesizing the two subjects in a subsequent follow-up. While I will explain the core foundational concepts in IQ science, I’ll also demonstrate why this is important in race-neutral terms by showing how the issues apply to education – and impact how we ought to think about, and practice, educational policy.

If minds are essentially blank slates which are carved into what they become by their environment, then the only thing limiting our ability as a society to turn anyone into anything at all is the skill of our teachers. Teachers, who influence most of the mind-shaping period of childhood, are the ones who deserve the most praise when people succeed and who deserve the most scorn when people fail.

There’s a saying one often sees on motivational posters for educators: “Teachers plant the seeds of knowledge that last a lifetime.”

But what if people themselves are already more like seeds than soil?

Soil is an empty receptacle that will generally grow whatever you can plant in it. If a gardener chooses to plant oak seeds instead of apricot seeds, then by virtue of that action, he is responsible for the fact that his garden grew oak trees instead of apricots.

On the other hand, the seed depends on certain elements in its environment in order to grow properly, but it already comes with its own built-in “blueprint” for what it is going to become, even when it is still indistinguishable from any other seed. The gardener deserves credit for watering his plants and ensuring the health of his soil, but he is not responsible for the fact that an oak seed becomes an oak tree. Its environment can stunt its capacity to grow, but its nature comes from within.

Are children like soil, passively waiting to grow whatever type of seed the gardeners of education choose to plant in them – or are they more like seeds, unfolding into what they will become according to their own internal blueprints, requiring only that their environment contains the preconditions to allow this process to take place?

If we assume that people are like soil, then we will take the fact that one group excels over another in a given subject as evidence that the first group is getting too much, and the second group is getting too little of our resources and attention. We’ll want to increase our focus on the second group until it achieves comparable outcomes. If people are blank slates, then their unequal outcomes must axiomatically be the result of the fact that we have treated them unequally — and therefore treated them unfairly.

But if children are more like seeds, then this will all be wasted effort. Pouring more water on a crape myrtle, or planting it in better soil, will never make it grow as tall as a redwood. And if you try to make that happen, you’ll waste incredible amounts of time and resources that could have achieved something far more productive if used in another way.

When it comes down to it, you simply have to accept crape myrtle seeds and redwood seeds for what they are. You’ll never grow the world’s tallest tree by planting crape myrtles, but you wouldn’t want to plant redwoods in your front yard. The key is to first accept them for what they are so that you can find places where their inherent traits fit in appropriately.

There is another important upshot of this distinction between seeds and soil. Suppose we had a variety of seeds, and we didn’t know what they were, and we needed to create the tallest row of trees possible. They’ve all been placed in equally bad soil so far, so they’re all withered, and it’s impossible to tell if some would naturally grow to be taller than the others if placed in better soil. In this scenario, what should you do?

As we discovered which seeds responded to being watered and placed in good soil by growing taller than the others, we would want to devote even more of our time and resources to those trees, and even less to those that still seemed to come up short once placed in better soil. We have limited time and resources on hand to produce the outcomes we need to achieve, and we will get far better dividends by investing in the better seeds than to expend them on those that lag behind.

The application to people is obvious: if people are more like seeds than soil, then failing to devote more resources to the most gifted is a far greater sin than failing to do so for those who lag behind. The most gifted are like redwoods: in a proper environment, they’ll grow to become the tallest trees on Earth. By impoverishing their environment, you can stunt their development and make it seem as though the difference between redwoods and crape myrtles isn’t as great as it really is. But the redwood doesn’t owe the fact that it is a redwood to its environment: a crape myrtle planted in the same soil will never grow as tall. If we neglect the most intelligent children in a vain attempt to let slower children catch up, we aren’t just wasting time, we’re stunting the growth of those redwoods while trying in vain to make the crabapples grow equally tall.

In fact, some educational systems do this.

Germany, for example, tracks children into different types of schools ^[4] based on teachers’ and parents’ assessment of their potential, beginning as early as fifth grade.

So, what has this produced?

An unemployment rate that is half ^[5] that of the United States, and a world-renowned reputation for high-quality products like the BMW. Students of low-to-average intellectual ability are directed towards apprenticeships rather than universities.

Rather than attempting to turn crabapples into redwoods, the German system aims to plant crabapples in their most appropriate place and tries to make them into the best crabapples they can be. In the end, this serves the best interests of everyone, from the workers themselves to the national economy of Germany as a whole.

Yet, Left-wing critics, including Vernor Muñoz, whose report to the UN on the “right to education ^[6]” gave Germany low marks, describe ^[7] the German system as an “anachronism” and as a “refuge for the privileged” which “emphasizes social inequality.”

Sure. Clearly, Germany should become more like the United States, where spending on K-12 education, even once adjusted for inflation, has roughly tripled ^[8] over the last four decades, and yet scores on reading, math, and science have remained perfectly flat.

While most Americans polled in 2007 expressed the belief that the biggest problem with public schooling is insufficient funding ^[9], the last four decades have in fact been a national experiment in rampantly increased educational spending – and the results of that experiment have been clear: as a society, no one, including our children, has benefited ^[10] from this massive influx of resources into education.

The proponent of the people-as-seeds perspective can easily explain this discrepancy: placing crabapples in better soil won’t turn them into redwoods. But the proponent of the people-as-soil perspective has a serious problem: how could we add this much additional fertilizer into the soil and see literally no increase in our trees’ height? That just doesn’t make sense.

Thankfully, science has reached the stage where it can answer this question once and for all. And the evidence is clear: people are not soil as much as they are seeds. To explain what the science says about this, we’ll have to perform a rundown of a few basic concepts.

First: heritability.

This is the concept that all of the studies we usually perform to try to estimate “how genetic” a behavior is are going to be measuring. Strictly speaking, how heritable something is and “how genetic” it is are not the same thing. The distinction is that heritability measurements do not measure the total influence that an individual’s genes have on that individual’s behavior. As we’ll see in a moment, heritability estimates can both overestimate or underestimate “how genetic” something is in this sense.

What these studies do is take for granted the amount of currently seen variation in behavior and personality between individuals in a given population, and then estimate how much of that variation is the result of differences between those individuals’ genes or environments. Thus, without any change in “how genetic” a behavior or personality trait is, the heritability of that trait can change! So heritability is a relative, and not an absolute, value.

I’ll proceed with examples.

If we study the heritability of height by looking at the United States in 2017, we’re going to find a very high value for that heritability. It is mostly genes that determine who is taller in the United States in 2017. But this is because very few people are being exposed to the environmental influences that can influence how tall people grow to be as adults. For instance, very few people in the United States in 2017 experience the kind of severe caloric deprivation it takes to stunt their physical growth. If half of the United States were to experience an economic crash in 2018, and this kind of severe caloric deprivation appeared again, what would happen when we remeasured the heritability of height in the United States in 2018? The heritability would fall significantly, because an environmental factor would then explain a much larger proportion of the differences in height found between the United States’ two halves – the one where severe caloric deprivation is prevalent and the one where it is not.

But heritability estimates can also underestimate the total degree to which a trait “is genetic” as well. We know, for example, that there is a small minority of people who can spend years smoking cigarettes and still have perfectly healthy lungs ^[11]. We know that this is due to the protective effect of a few unique genes which studies have now precisely identified ^[12].

If we studied the heritability of lung cancer today, smoking would be the most significant predictor of someone developing it, and we would find an extremely low value for heritability. But what if this situation were to change? What if these “good genes” that protect against the damage from smoking were to spread throughout most of the population, and smoking as a habit became more prevalent?

Well, suddenly the heritability of lung cancer in America would become extremely high, because now that almost everyone is exposed to cigarette smoke, it is a less effective way of predicting who will develop lung cancer than looking at who has the protective genes. With almost everyone being exposed to cigarette smoke, knowing someone had been exposed wouldn’t give you very solid grounds for predicting how things will turn out in the future.

In short, heritability is as close as we can get to trying to estimate “how genetic” a trait or behavior is. While it doesn’t tell us how responsible an individual’s genes are for that individual’s traits or behaviors, it can tell us how responsible genes are for the differences found within groups of people in a large population.

How do heritability studies accomplish that?

Traditional heritability studies primarily focus on two techniques. The first technique is to control the environment in order to see how much variation between individuals remains (since what remains is the amount of variation that is due to genetics). The second technique is to control for genes in order to see how much variation remains (since what remains is the amount of variation that is the result of the environment). You can achieve the former by comparing adopted and biological children raised in the same home from young ages. You can achieve the latter by looking at identical twins raised separately. Of course, this is not exhaustive; there are many other techniques you can employ, such as measuring the similarity found between identical and non-identical twins, and comparing this with the proportion of genes shared by them, but for the purposes of this article I’m going to focus on the more straightforward methods.

Without exception, the results of all of these studies show that personality and intellectual ability are very heritable: in other words, when people in the modern world differ in IQ, that difference is owed to genes more than it is to environmental factors. What this means in concrete terms is that adopted children grow up to be more like their biological parents than they are like the siblings they grew up with, or their adoptive parents. Yet at the same time, identical twins grow up to be significantly more like each other than non-twin siblings do. And this happens even if their childhoods never intersect because they grew up in different homes.

Now let’s discuss the heritability of IQ.

By the lowest estimates made by nearly anyone, anywhere, in any respectable academic position, the heritability of IQ is at least around fifty percent. Scientific debate is no longer over whether IQ is heritable. There is literally no respectable scientific theory which supposes that IQ is determined primarily by the environment. The debate is between “environmentalists” and “hereditarians,” but even those “environmentalists” take the position that IQ is somewhere around fifty percent heritable. The “hereditarians” who take a stronger stance simply raise that estimate to around eighty percent.

To get a more tangible idea of what these values mean, let’s plug some overly simplified numbers into a hypothetical scenario.

Suppose that in the population we’re studying, the range in IQ stretches from scores of exactly eighty at the low end to exactly one hundred twenty at the top. If IQ were fifty percent heritable in this population, then people would be born with genes that set their IQ somewhere between ninety and one hundred ten – then the very best or worst environments that any part of this population is ever exposed to would be capable of adding or taking away another ten points to determine a person’s IQ. The total range of IQ in this population is forty points, and genes would be responsible for half of that, which means genes would be responsible for twenty total IQ points. Thus, if we start in the middle at one hundred, genes would first add or take away up to ten total points in either direction, and then the environment would add or take away up to ten more points.

Thus, someone born with the worst genes for IQ seen in this population would start at ninety. They could reach an IQ as high as one hundred with the help of the most beneficial environmental boost possible, and being placed in the most corrosive environment seen anywhere in this population could cause their IQ to fall to as low as eighty. Meanwhile, someone born with the best genes for IQ seen in this population could only reach an IQ of one hundred by being exposed to the worst environment ever seen in this population.

But he will never, under any circumstances, perform worse on IQ tests than the individual with the worst genes for IQ in this population; it would take exposure to the worst environment possible just to make him do equally as poorly as the individual with the worst genes for IQ can do only with the help of the best environment possible.

If you can, try to let it sink in that this is what the “environmentalists” in the modern scientific debate believe to be true regarding the hereditability of IQ. Even in this scenario, as you can see, genes are still extremely significant for explaining the differences between individuals.

On the other hand, if the hereditarians were correct about this population and its IQ were found to be eighty percent heritable, then a person would be born with genes that would place their IQ somewhere between eighty-four and one hundred sixteen. Then the best and worst environments could add or take away at most only four points to produce that individual’s IQ.

The total range in variation between an IQ of eighty and an IQ of one hundred twenty is still forty points. If genes are responsible for eighty percent of that variation, then they are responsible for thirty-two total points. Thus, starting in the middle at one hundred, a person’s genes start them off with up to an extra sixteen points for or against them, and then the environment fills in the remaining twenty percent of variation by adding or taking away up to four points. This might not be “genetic determinism,” but damn if it isn’t close.

Children and Adults

One important point that gets missed in many entry-level discussions of this topic is that the heritability of IQ changes across different age groups. In children, the heritability of IQ is relatively low. In one’s late teens and in both younger and older adults, the heritability of IQ rises substantially. Environmentalist arguments have often tried to draw power from studies that solely looked at the heritability of IQ in children. In one study we’ll look at in the next entry in this series, the environmental influence over the IQ of children adopted into the homes of parents of a different race was large – and the heritability was low.

“Case closed!” the environmentalists wanted to shout – except that when a follow-up was performed ten years later, that environmental influence had almost totally washed out. The IQ of those children’s biological parents was, once again, the most significant predictor of their current IQ – not the IQs of the adoptive parents who had raised them or the siblings they grew up with.

The best way to think about this discrepancy is to imagine that children come with blueprints given to them by their parents which lay out the plan for what their adult IQ is going to be. However, the speed at which those children are exposed to different environmental stimuli will have a significant impact on how fast they put that blueprint together.

Can we infer from the heritability of individual IQ that there is a heritability of IQ between races?

Technically, no. That is, again, because heritability is a relative value. We have to establish that the environment that two individuals are exposed to is the same before we can estimate the amount of variation left over that must be due to genetics. Since the Left-wing argument is that members of different racial groups are exposed to systematically different environments because of their race, it would beg the question of whether or not what is true of the heritability of IQ between two white individuals must also be true for the heritability of IQ between a white individual and a black one. That is why an important part of this debate will always belong to sociology – a topic I’ve taken a reasonable start on addressing in many of my previous articles (“Is the War on Drugs Racist? ^[13]”, “An Open Letter to Jesse Williams ^[14],” and “Employers Hate Blacks, but They Love ‘Ebony’? ^[15]”).

Obviously, we wouldn’t be able to learn anything interesting by comparing poor black individuals to wealthy white individuals. If all blacks were poor, and all whites were from wealthy homes, then using the methods of heritability studies would be absolutely incapable of giving us any meaningful information about the causes of the differences between black and white IQs. Fortunately, I think most people are aware by now that not all blacks are poor and not all whites come from wealthy homes. But it does take extra work to figure out the cause of the differences between two different groups, even once you know the causes of the differences between the various individuals within those different groups. We’ll take a look in the next article at how far the science is capable of taking us on that question.

Further reading: Steve Sailer, ”T ^[16]he College Paradox: Not Everyone Gains by Higher Education ^[16],” VDARE.