Some people are naturally smarter than others. Most of us know this intuitively, and reams of scientific evidence prove it, but few are willing to talk about it openly.

This taboo, contends the academic and Marxist essayist Fredrik deBoer in The Cult of Smart, distorts our educational practices, our ideals of “meritocracy,” and our public policy.

The Cult of Smart will be a success if it forces the Left to confront the findings of modern genetics. Over here on the other side of the aisle, though, it feels as if Charles Murray’s 2008 book Real Education has been rewritten from a different angle, with a series of half-baked left-wing policy proposals tacked on at the end. It’s not a bad read by any stretch, but it’s not too satisfying either.

Many who study American education find themselves distressed by gaps among groups — black vs. white, rich vs. poor, and so on. DeBoer, by contrast, finds himself focused on gaps within groups. As the recent college-admissions scandal showed, even wealthy kids with every resource at their disposal sometimes can’t hack it in high school and need their parents to bribe them into a decent university. As an educator himself, deBoer has seen that within any school, no matter how demographically homogeneous, there’s a wide variety of student ability. Even when everyone has equal opportunities, there will be unequal results.

Why is that? Is it purely that the kids who earn straight “A”s try harder? Well, no; a lot of it is genes. For decades, researchers have been looking at various types of siblings — identical and fraternal twins, adoptive siblings, etc. — and showing that people tend to be more academically and intellectually similar to each other the more genes they share. Sharing a home, which normally means sharing the same schools too, has a far smaller effect. Newer research has even begun to locate the specific genes at work. These basic findings are not scientifically controversial, and deBoer doesn’t feel obligated to make a very detailed case for them.

To be clear, deBoer does not argue that all differences in educational performance are genetic. He specifically rejects the idea that racial gaps have a genetic component, for example. What he does say is that there are profound differences in academic ability from person to person, and that our society has not bothered to grapple with the consequences of that fact.

This is most clear in education, where deBoer has spent much of his professional life: He’s taught “students from kindergarten through graduate school,” “black and Hispanic and Asian and white students, men and women, boys and girls,” and “classes as small as eight students in intimate conversation groups and as large as dozens in large lecture halls”; he’s worked “in a high-minority and largely poor public school district” and tutored “the sons and daughters of the immensely wealthy.” In his experience, school hallways are plastered with inspirational posters telling kids they can do anything they want if they just try hard enough. Educators are urged to enforce strict graduation requirements and to increase graduation rates simultaneously, which is a problem if many kids are incapable of meeting strict criteria. (Algebra requirements in particular tend to trip kids up.) Education reformers expect teachers to get all kids up to “grade level” or “proficiency.” Teachers and schools are blamed or praised based on the test scores of their students, even though the scores are far more a function of the abilities and backgrounds of the kids than they are of the educators’ skills.

Meanwhile, our broader culture has fallen victim to a “cult of smart” in which academic achievement is equated with merit and “equality of opportunity” is seen as the key goal, with little attention paid to the fact that such a system largely rewards those who have hit the genetic lottery — while justifying the poverty of those who haven’t. An obsession with academic meritocracy also puts enormous pressure on higher-achieving kids to sacrifice everything to get into the best schools. To not go to college at all is seen as an incredible personal failure.

DeBoer is right about all of this, and these are the strongest parts of the book. But then he wraps up with two chapters that focus on improving public policy.

There are some good ideas here, especially in the first, “Realistic Reforms.” Education reformers should drop their push for higher standards for all students, instead giving schools more flexibility to accommodate kids of different ability levels. They should also end the college-for-all craze, both because not all students are cut out for college and because giving more people college degrees just waters down the value of the credential. Even in this chapter, however, deBoer pushes into some dubious territory: Lowering the legal dropout age to twelve, eliminating charter schools, and providing universal child care and after-school care strike me as much less realistic and much less desirable.

And in the next chapter, deBoer descends into a weird hodgepodge of ideas that don’t have much to do with the rest of the book. He endorses the assorted aims of the modern Left, including Medicare for All, a universal basic income, free college, and student-debt forgiveness. There is a connection here to deBoer’s broader themes — if the market is unfair to people who inherited weaker skills through no fault of their own, it’s not hard to make the case for some redistribution. (This is something even the libertarian Murray has conceded.) But the pros and cons of these specific policies are really outside the scope of this book, and as a result these sections feel like a digression.

From there, deBoer proposes a fantastical socialist utopia in which markets don’t exist. To illustrate his goals, he writes that

to socialize housing means that the people would take community control of the housing stock themselves and distribute it based on need rather than on the profit motive. The goal is not to transform the distribution of power and wealth within an economy but to bring about the disintegration of the concept of an economy, to achieve a society governed by the dictates of human need rather than the dictates of the accumulation of wealth.

Didn’t that go rather poorly in the USSR? I hear you asking. Well, actually, real communism hasn’t been tried yet: Even Marx himself thought there would need to be a period of capitalist development before communism would be possible, and while humans weren’t rich enough to make that work in the Soviet era, now we’re able to forget about markets and just do whatever we feel like doing. Okay, maybe not whatever we want, because some people will still be naturally cut out for certain roles, and “we as a society will have to carefully navigate the relationship between social need and ability.” But whatever you do, don’t worry about human nature getting in the way. That’s merely “a construct whose boundaries are defined by whatever is convenient at the moment,” and people will do all sorts of productive things even if they don’t need to in order to earn money. Everyone has a niche to fill.

Earlier in the book, deBoer discusses research finding that a country’s economic development depends heavily on the intellectual achievements of the top 5 percent of the population. He should take more seriously the possibilities that those folks need market incentives to drive them to better performance, even if they’re taxed to help the less gifted and they’re regulated to rein in their worst instincts; that markets really are the best way of matching people with different talents to the roles they’re suited for; and that, to keep improving, humanity will always need capitalism, no matter how wealthy and technologically developed societies become.

But I’m not going to convince him of that in a small fraction of a book review, just as he didn’t convert me to Marxism in a small fraction of a book about a completely different topic.