Is grade inflation a real problem?

Mar 4 JDN 2458182

You can’t spend much time teaching at the university level and not hear someone complain about “grade inflation”. Almost every professor seems to believe in it, and yet they must all be participating in it, if it’s really such a widespread problem.

This could be explained as a collective action problem, a Tragedy of the Commons: If the incentives are always to have the students with the highest grades—perhaps because of administrative pressure, or in order to get better reviews from students—then even if all professors would prefer a harsher grading scheme, no individual professor can afford to deviate from the prevailing norms.

But in fact I think there is a much simpler explanation: Grade inflation doesn’t exist.

In economic growth theory, economists make a sharp distinction between inflation—increase in prices without change in underlying fundamentals—and growth—increase in the real value of output. I contend that there is no such thing as grade inflation—what we are in fact observing is grade growth.
Am I saying that students are actually smarter now than they were 30 years ago?

Yes. That’s exactly what I’m saying.

But don’t take it from me. Take it from the decades of research on the Flynn Effect: IQ scores have been rising worldwide at a rate of about 0.3 IQ points per year for as long as we’ve been keeping good records. Students today are about 10 IQ points smarter than students 30 years ago—a 2018 IQ score of 95 is equivalent to a 1988 score of 105, which is equivalent to a 1958 score of 115. There is reason to think this trend won’t continue indefinitely, since the effect is mainly concentrated at the bottom end of the distribution; but it has continued for quite some time already.

This by itself would probably be enough to explain the observed increase in grades, but there’s more: College students are also a self-selected sample, admitted precisely because they were believed to be the smartest individuals in the application pool. Rising grades at top institutions are easily explained by rising selectivity at top schools: Harvard now accepts 5.6% of applicants. In 1942, Harvard accepted 92% of applicants. The odds of getting in have fallen from 9:1 in favor to 19:1 against. Today, you need a 4.0 GPA, a 36 ACT in every category, glowing letters of recommendation, and hundreds of hours of extracurricular activities (or a family member who donated millions of dollars, of course) to get into Harvard. In the 1940s, you needed a high school diploma and a B average.

In fact, when educational researchers have tried to quantitatively study the phenomenon of “grade inflation”, they usually come back with the result that they simply can’t find it. The US department of education conducted a study in 1995 showing that average university grades had declined since 1965. Given that the Flynn effect raised IQ by almost 10 points during that time, maybe we should be panicking about grade deflation.

It really wouldn’t be hard to make that case: “Back in my day, you could get an A just by knowing basic algebra! Now they want these kids to take partial derivatives?” “We used to just memorize facts to ace the exam; but now teachers keep asking for reasoning and critical thinking?”

More recently, a study in 2013 found that grades rose at the high school level, but fell at the college level, and showed no evidence of losing any informativeness as a signaling mechanism. The only recent study I could find showing genuinely compelling evidence for grade inflation was a 2017 study of UK students estimating that grades are growing about twice as fast as the Flynn effect alone would predict. Most studies don’t even consider the possibility that students are smarter than they used to be—they just take it for granted that any increase in average grades constitutes grade inflation. Many of them don’t even control for the increase in selectivity—here’s one using the fact that Harvard’s average rose from 2.7 to 3.4 from 1960 to 2000 as evidence of “grade inflation” when Harvard’s acceptance rate fell from almost 30% to only 10% during that period.

Indeed, the real mystery is why so many professors believe in grade inflation, when the evidence for it is so astonishingly weak.

I think it’s availability heuristic. Who are professors? They are the cream of the crop. They aced their way through high school, college, and graduate school, then got hired and earned tenure—they were one of a handful of individuals who won a fierce competition with hundreds of competitors at each stage. There are over 320 million people in the US, and only 1.3 million college faculty. This means that college professors represent about the top 0.4% of high-scoring students.

Combine that with the fact that human beings assort positively (we like to spend time with people who are similar to us) and use availability heuristic (we judge how likely something is based on how many times we have seen it).

Thus, when a professor compares to her own experience of college, she is remembering her fellow top-scoring students at elite educational institutions. She is recalling the extreme intellectual demands she had to meet to get where she is today, and erroneously assuming that these are representative of most the population of her generation. She probably went to school at one of a handful of elite institutions, even if she now teaches at a mid-level community college: three quarters of college faculty come from the top one quarter of graduate schools.

And now she compares to the students she has to teach, most of whom would not be able to meet such demands—but of course most people in her generation couldn’t either. She frets for the future of humanity only because not everyone is a genius like her.

Throw in the Curse of Knowledge: The professor doesn’t remember how hard it was to learn what she has learned so far, and so the fact that it seems easy now makes her think it was easy all along. “How can they not know how to take partial derivatives!?” Well, let’s see… were you born knowing how to take partial derivatives?

Giving a student an A for work far inferior to what you’d have done in their place isn’t unfair. Indeed, it would clearly be unfair to do anything less. You have years if not decades of additional education ahead of them, and you are from self-selected elite sample of highly intelligent individuals. Expecting everyone to perform as well as you would is simply setting up most of the population for failure.

There are potential incentives for grade inflation that do concern me: In particular, a lot of international student visas and scholarship programs insist upon maintaining a B or even A- average to continue. Professors are understandably loathe to condemn a student to having to drop out or return to their home country just because they scored 81% instead of 84% on the final exam. If we really intend to make C the average score, then students shouldn’t lose funding or visas just for scoring a B-. Indeed, I have trouble defending any threshold above outright failing—which is to say, a minimum score of D-. If you pass your classes, that should be good enough to keep your funding.

Yet apparently even this isn’t creating too much upward bias, as students who are 10 IQ points smarter are still getting about the same scores as their forebears. We should be celebrating that our population is getting smarter, but instead we’re panicking over “easy grading”.

But kids these days, am I right?

Why Millennials feel “entitled”

JDN 2457064

I’m sure you’ve already heard this plenty of times before, but just in case here are a few particularly notable examples: “Millennials are entitled.” “Millennials are narcissistic.” “Millennials expect instant gratification.

Fortunately there are some more nuanced takes as well: One survey shows that we are perceived as “entitled” and “self-centered” but also “hardworking” and “tolerant”. This article convincingly argues that Baby Boomers show at least as much ‘entitlement’ as we do. Another article points out that young people have been called these sorts of names for decades—though actually the proper figure is centuries.

Though some of the ‘defenses’ leave a lot to be desired: “OK, admittedly, people do live at home. But that’s only because we really like our parents. And why shouldn’t we?” Uh, no, that’s not it. Nor is it that we’re holding off on getting married. The reason we live with our parents is that we have no money and can’t pay for our own housing. And why aren’t we getting married? Because we can’t afford to pay for a wedding, much less buy a home and start raising kids. (Since the time I drafted this for Patreon and it went live, yet another article hand-wringing over why we’re not getting married was publishedin Scientific American, of all places.)

Are we not buying cars because we don’t like cars? No, we’re not buying cars because we can’t afford to pay for them.

The defining attributes of the Millennial generation are that we are young (by definition) and broke (with very few exceptions). We’re not uniquely narcissistic or even tolerant; younger generations always have these qualities.

But there may be some kernel of truth here, which is that we were promised a lot more than we got.

Educational attainment in the United States is the highest it has ever been. Take a look at this graph from the US Department of Education:

Percentage of 25- to 29-year-olds who completed a bachelor’s or higher degree, by race/ethnicity: Selected years, 1990–2014

education_attainment_race

More young people of every demographic except American Indians now have college degrees (and those figures fluctuate a lot because of small samples—whether my high school had an achievement gap for American Indians depended upon how I self-identified on the form, because there were only two others and I was tied for the highest GPA).

Even the IQ of Millennials is higher than that of our parents’ generation, which is higher than their parents’ generation; (measured) intelligence rises over time in what is called the Flynn Effect. IQ tests have to be adjusted to be harder by about 3 points every 10 years because otherwise the average score would stop being 100.

As your level of education increases, your income tends to go up and your unemployment tends to go down. In 2014, while people with doctorates or professional degrees had about 2% unemployment and made a median income of $1590 per week, people without even high school diplomas had about 9% unemployment and made a median income of only $490 per week. The Bureau of Labor Statistics has a nice little bar chart of these differences:

education_employment_earnings

Now the difference is not quite as stark. With the most recent data, the unemployment rate is 6.7% for people without a high school diploma and 2.5% for people with a bachelor’s degree or higher.

But that’s for the population as a whole. What about the population of people 18 to 35, those of us commonly known as Millennials?

Well, first of all, our unemployment rate overall is much higher. With the most recent data, unemployment among people ages 20-24 is a whopping 9.4%. For ages 25 to 34 it gets better, 5.3%; but it’s still much worse than unemployment at ages 35-44 (4.0%), 45-54 (3.6%), or 55+ (3.2%). Overall, unemployment among Millennials is about 6.7% while unemployment among Baby Boomers is about 3.2%, half as much. (Gen X is in between, but a lot closer to the Boomers at around 3.8%.)

It was hard to find data specifically breaking it down by both age and education at the same time, but the hunt was worth it.

Among people age 20-24 not in school:

Without a high school diploma, 328,000 are unemployed, out of 1,501,000 in the labor force. That’s an unemployment rate of 21.9%. Not a typo, that’s 21.9%.

With only a high school diploma, 752,000 are unemployed, out of 5,498,000 in the labor force. That’s an unemployment rate of 13.7%.

With some college but no bachelor’s degree, 281,000 are unemployed, out of 3,620,000 in the labor force. That’s an unemployment rate of 7.7%.

With a bachelor’s degree, 90,000 are unemployed, out of 2,313,000 in the labor force. That’s an unemployment rate of 3.9%.

What this means is that someone 24 or under needs to have a bachelor’s degree in order to have the same overall unemployment rate that people from Gen X have in general, and even with a bachelor’s degree, people under 24 still have a higher unemployment rate than what Baby Boomers simply have by default. If someone under 24 doesn’t even have a high school diploma, forget it; their unemployment rate is comparable to the population unemployment rate at the trough of the Great Depression.

In other words, we need to have college degrees just to match the general population older than us, of whom only 20% have a college degree; and there is absolutely nothing a Millennial can do in terms of education to ever have the tiny unemployment rate (about 1.5%) of Baby Boomers with professional degrees. (Be born White, be in perfect health, have a professional degree, have rich parents, and live in a city with very high employment, and you just might be able to pull it off.)

So, why do Millennials feel like a college degree should “entitle” us to a job?

Because it does for everyone else.

Why do we feel “entitled” to a higher standard of living than the one we have?
Take a look at this graph of GDP per capita in the US:

US_GDP_per_capita

You may notice a rather sudden dip in 2009, around the time most Millennials graduated from college and entered the labor force. On the next graph, I’ve added a curve approximating what it would look like if the previous trend had continued:

US_GDP_per_capita_trend

(There’s a lot on this graph for wonks like me. You can see how the unit-root hypothesis seemed to fail in the previous four recessions, where economic output rose back up to potential; but it clearly held in this recession, and there was a permanent loss of output. It also failed in the recession before that. So what’s the deal? Why do we recover from some recessions and take a permanent blow from others?)

If the Great Recession hadn’t happened, instead of per-capita GDP being about $46,000 in 2005 dollars, it would instead be closer to $51,000 in 2005 dollars. In today’s money, that means our current $56,000 would be instead closer to $62,000. If we had simply stayed on the growth trajectory we were promised, we’d be almost 10 log points richer (11% for the uninitiated).

So, why do Millennials feel “entitled” to things we don’t have? In a word, macroeconomics.

People anchored their expectations of what the world would be like on forecasts. The forecasts said that the skies were clear and economic growth would continue apace; so naturally we assumed that this was true. When the floor fell out from under our economy, only a few brilliant and/or lucky economists saw it coming; even people who were paying quite close attention were blindsided. We were raised in a world where economic growth promised rising standard of living and steady employment for the rest of our lives. And then the storm hit, and we were thrown into a world of poverty and unemployment—and especially poverty and unemployment for us.

We are angry about how we had been promised more than we were given, angry about how the distribution of what wealth we do have gets ever more unequal. We are angry that our parents’ generation promised what they could not deliver, and angry that it was their own blind worship of the corrupt banking system that allowed the crash to happen.

And because we are angry and demand a fairer share, they have the audacity to call us “narcissistic”.

The irrationality of racism

JDN 2457039 EST 12:07.

I thought about making today’s post about the crazy currency crisis in Switzerland, but currency exchange rates aren’t really my area of expertise; this is much more in Krugman’s bailiwick, so you should probably read what Krugman says about the situation. There is one thing I’d like to say, however: I think there is a really easy way to create credible inflation and boost aggregate demand, but for some reason nobody is ever willing to do it: Give people money. Emphasis here on the people—not banks. Don’t adjust interest rates or currency pegs, don’t engage in quantitative easing. Give people money. Actually write a bunch of checks, presumably in the form of refundable tax rebates.

The only reason I can think of that economists don’t do this is they are afraid of helping poor people. They wouldn’t put it that way; maybe they’d say they want to avoid “moral hazard” or “perverse incentives”. But those fears didn’t stop them from loaning $2 trillion to banks or adding $4 trillion to the monetary base; they didn’t stop them from fighting for continued financial deregulation when what the world economy most desperately needs is stronger financial regulation. Our whole derivatives market practically oozes moral hazard and perverse incentives, but they aren’t willing to shut down that quadrillion-dollar con game. So that can’t be the actual fear. No, it has to be a fear of helping poor people instead of rich people, as though “capitalism” meant a system in which we squeeze the poor as tight as we can and heap all possible advantages upon those who are already wealthy. No, that’s called feudalism. Capitalism is supposed to be a system where markets are structured to provide free and fair competition, with everyone on a level playing field.

A basic income is a fundamentally capitalist policy, which maintains equal opportunity with a minimum of government intervention and allows the market to flourish. I suppose if you want to say that all taxation and government spending is “socialist”, fine; then every nation that has ever maintained stability for more than a decade has been in this sense “socialist”. Every soldier, firefighter and police officer paid by a government payroll is now part of a “socialist” system. Okay, as long as we’re consistent about that; but now you really can’t say that socialism is harmful; on the contrary, on this definition socialism is necessary for capitalism. In order to maintain security of property, enforcement of contracts, and equality of opportunity, you need government. Maybe we should just give up on the words entirely, and speak more clearly about what specific policies we want. If I don’t get to say that a basic income is “capitalist”, you don’t get to say financial deregulation is “capitalist”. Better yet, how about you can’t even call it “deregulation”? You have to actually argue in front of a crowd of people that it should be legal for banks to lie to them, and there should be no serious repercussions for any bank that cheats, steals, colludes, or even launders money for terrorists. That is, after all, what financial deregulation actually does in the real world.

Okay, that’s enough about that.

My birthday is coming up this Monday; thus completes my 27th revolution around the Sun. With birthdays come thoughts of ancestry: Though I appear White, I am legally one-quarter Native American, and my total ethnic mix includes English, German, Irish, Mohawk, and Chippewa.

Biologically, what exactly does that mean? Next to nothing.

Human genetic diversity is a real thing, and there are genetic links to not only dozens of genetic diseases and propensity toward certain types of cancer, but also personality and intelligence. There are also of course genes for skin pigmentation.

The human population does exhibit some genetic clustering, but the categories are not what you’re probably used to: Good examples of relatively well-defined genetic clusters include Ashkenazi, Papuan, and Mbuti. There are also many different haplogroups, such as mitochondrial haplogroups L3 and CZ.

Maybe you could even make a case for the “races” East Asian, South Asian, Pacific Islander, and Native American, since the indigenous populations of these geographic areas largely do come from the same genetic clusters. Or you could make a bigger category and call them all “Asian”—but if you include Papuan and Aborigine in “Asian” you’d pretty much have to include Chippewa and Najavo as well.

But I think it tells you a lot about what “race” really means when you realize that the two “race” categories which are most salient to Americans are in fact the categories that are genetically most meaningless. “White” and “Black” are totally nonsensical genetic categorizations.

Let’s start with “Black”; defining a “Black” race is like defining a category of animals by the fact that they are all tinted red—foxes yes, dogs no; robins yes, swallows no; ladybirds yes, cockroaches no. There is more genetic diversity within Africa than there is outside of it. There are African populations that are more closely related to European populations than they are to other African populations. The only thing “Black” people have in common is that their skin is dark, which is due to convergent evolution: It’s not due to common ancestry, but a common environment. Dark skin has a direct survival benefit in climates with intense sunlight.  The similarity is literally skin deep.

What about “White”? Well, there are some fairly well-defined European genetic populations, so if we clustered those together we might be able to get something worth calling “White”. The problem is, that’s not how it happened. “White” is a club. The definition of who gets to be “White” has expanded over time, and even occasionally contracted. Originally Hebrew, Celtic, Hispanic, and Italian were not included (and Hebrew, for once, is actually a fairly sensible genetic category, as long as you restrict it to Ashkenazi), but then later they were. But now that we’ve got a lot of poor people coming in from Mexico, we don’t quite think of Hispanics as “White” anymore. We actually watched Arabs lose their “White” card in real-time in 2001; before 9/11, they were “White”; now, “Arab” is a separate thing. And “Muslim” is even treated like a race now, which is like making a racial category of “Keynesians”—never forget that Islam is above all a belief system.

Actually, “White privilege” is almost a tautology—the privilege isn’t given to people who were already defined as “White”, the privilege is to be called “White”. The privilege is to have your ancestors counted in the “White” category so that they can be given rights, while people who are not in the category are denied those rights. There does seem to be a certain degree of restriction by appearance—to my knowledge, no population with skin as dark as Kenyans has ever been considered “White”, and Anglo-Saxons and Nordics have always been included—but the category is flexible to political and social changes.

But really I hate that word “privilege”, because it gets the whole situation backwards. When you talk about “White privilege”, you make it sound as though the problem with racism is that it gives unfair advantages to White people (or to people arbitrarily defined as “White”). No, the problem is that people who are not White are denied rights. It isn’t what White people have that’s wrong; it’s what Black people don’t have. Equating those two things creates a vision of the world as zero-sum, in which each gain for me is a loss for you.

Here’s the thing about zero-sum games: All outcomes are Pareto-efficient. Remember when I talked about Pareto-efficiency? As a quick refresher, an outcome is Pareto-efficient if there is no way for one person to be made better off without making someone else worse off. In general, it’s pretty hard to disagree that, other things equal, Pareto-efficiency is a good thing, and Pareto-inefficiency is a bad thing. But if racism were about “White privilege” and the game were zero-sum, racism would have to be Pareto-efficient.

In fact, racism is Pareto-inefficient, and that is part of why it is so obviously bad. It harms literally billions of people, and benefits basically no one. Maybe there are a few individuals who are actually, all things considered, better off than they would have been if racism had not existed. But there are certainly not very many such people, and in fact I’m not sure there are any at all. If there are any, it would mean that technically racism is not Pareto-inefficient—but it is definitely very close. At the very least, the damage caused by racism is several orders of magnitude larger than any benefits incurred.

That’s why the “privilege” language, while well-intentioned, is so insidious; it tells White people that racism means taking things away from them. Many of these people are already in dire straits—broke, unemployed, or even homeless—so taking away what they have sounds particularly awful. Of course they’d be hostile to or at least dubious of attempts to reduce racism. You just told them that racism is the only thing keeping them afloat! In fact, quite the opposite is the case: Poor White people are, second only to poor Black people, those who stand the most to gain from a more just society. David Koch and Donald Trump should be worried; we will probably have to take most of their money away in order to achieve social justice. (Bill Gates knows we’ll have to take most of his money away, but he’s okay with that; in fact he may end up giving it away before we get around to taking it.) But the average White person will almost certainly be better off than they were.

Why does it seem like there are benefits to racism? Again, because people are accustomed to thinking of the world as zero-sum. One person is denied a benefit, so that benefit must go somewhere else right? Nope—it can just disappear entirely, and in this case typically does.

When a Black person is denied a job in favor of a White person who is less qualified, doesn’t that White person benefit? Uh, no, actually, not really. They have been hired for a job that isn’t an optimal fit for them; they aren’t working to their comparative advantage, and that Black person isn’t either and may not be working at all. The total output of the economy will be thereby reduced slightly. When this happens millions of times, the total reduction in output can be quite substantial, and as a result that White person was hired at $30,000 for an unsuitable job when in a racism-free world they’d have been hired at $40,000 for a suitable one. A similar argument holds for sexism; men don’t benefit from getting jobs women are denied if one of those women would have invented a cure for prostate cancer.

Indeed, the empowerment of women and minorities is kind of the secret cheat code for creating a First World economy. The great successes of economic development—Korea, Japan, China, the US in WW2—had their successes precisely at a time when they suddenly started including women in manufacturing, effectively doubling their total labor capacity. Moreover, it’s pretty clear that the causation ran in this direction. Periods of economic growth are associated with increases in solidarity with other groups—and downturns with decreased solidarity—but the increase in women in the workforce was sudden and early while the increase in growth and total output was prolonged.

Racism is irrational. Indeed it is so obviously irrational that for decades now neoclassical economists have been insisting that there is no need for civil rights policy, affirmative action, etc. because the market will automatically eliminate racism by the rational profit motive. A more recent literature has attempted to show that, contrary to all appearances, racism actually is rational in some cases. Inevitably it relies upon either the background of a racist society (maybe Black people are, on average, genuinely less qualified, but it would only be because they’ve been given poorer opportunities), or an assumption of “discriminatory tastes”, which is basically giving up and redefining the utility function so that people simply get direct pleasure from being racists. Of course, on that sort of definition, you can basically justify any behavior as “rational”: Maybe he just enjoys banging his head against the wall! (A similar slipperiness is used by egoists to argue that caring for your children is actually “selfish”; well, it makes you happy, doesn’t it? Yes, but that’s not why we do it.)

There’s a much simpler way to understand this situation: Racism is irrational, and so is human behavior.

That isn’t a complete explanation, of course; and I think one major misunderstanding neoclassical economists have of cognitive economists is that they think this is what we do—we point out that something is irrational, and then high-five and go home. No, that’s not what we do. Finding the irrationality is just the start; next comes explaining the irrationality, understanding the irrationality, and finally—we haven’t reached this point in most cases—fixing the irrationality.

So what explains racism? In short, the tribal paradigm. Human beings evolved in an environment in which the most important factor in our survival and that of our offspring was not food supply or temperature or predators, it was tribal cohesion. With a cohesive tribe, we could find food, make clothes, fight off lions. Without one, we were helpless. Millions of years in this condition shaped our brains, programming them to treat threats to tribal cohesion as the greatest possible concern. We even reached the point where solidarity for the tribe actually began to dominate basic survival instincts: For a suicide bomber the unity of the tribe—be it Marxism for the Tamil Tigers or Islam for Al-Qaeda—is more important than his own life. We will do literally anything if we believe it is necessary to defend the identities we believe in.

And no, we rationalists are no exception here. We are indeed different from other groups; the beliefs that define us, unlike the beliefs of literally every other group that has ever existed, are actually rationally founded. The scientific method really isn’t just another religion, for unlike religion it actually works. But still, if push came to shove and we were forced to kill and die in order to defend rationality, we would; and maybe we’d even be right to do so. Maybe the French Revolution was, all things considered, a good thing—but it sure as hell wasn’t nonviolent.

This is the background we need to understand racism. It actually isn’t enough to show people that racism is harmful and irrational, because they are programmed not to care. As long as racial identification is the salient identity, the tribe by which we define ourselves, we will do anything to defend the cohesion of that tribe. It is not enough to show that racism is bad; we must in fact show that race doesn’t matter. Fortunately, this is easy, for as I explained above, race does not actually exist.

That makes racism in some sense easier to deal with than sexism, because the very categories of races upon which it is based are fundamentally faulty. Sexes, on the other hand, are definitely a real thing. Males and females actually are genetically different in important ways. Exactly how different in what ways is an open question, and what we do know is that for most of the really important traits like intelligence and personality the overlap outstrips the difference. (The really big, categorical differences all appear to be physical: Anatomy, size, testosterone.) But conquering sexism may always be a difficult balance, for there are certain differences we won’t be able to eliminate without altering DNA. That no more justifies sexism than the fact that height is partly genetic would justify denying rights to short people (which, actually, is something we do); but it does make matters complicated, because it’s difficult to know whether an observed difference (for instance, most pediatricians are female, while most neurosurgeons are male) is due to discrimination or innate differences.

Racism, on the other hand, is actually quite simple: Almost any statistically significant difference in behavior or outcome between races must be due to some form of discrimination somewhere down the line. Maybe it’s not discrimination right here, right now; maybe it’s discrimination years ago that denied opportunities, or discrimination against their ancestors that led them to inherit less generations later; but it almost has to be discrimination against someone somewhere, because it is only by social construction that races exist in the first place. I do say “almost” because I can think of a few exceptions: Black people are genuinely less likely to use tanning salons and genuinely more likely to need vitamin D supplements, but both of those things are directly due to skin pigmentation. They are also more likely to suffer from sickle-cell anemia, which is another convergent trait that evolved in tropical climates as a response to malaria. But unless you can think of a reason why employment outcomes would depend upon vitamin D, the huge difference in employment between Whites and Blacks really can’t be due to anything but discrimination.

I imagine most of my readers are more sophisticated than this, but just in case you’re wondering about the difference in IQ scores between Whites and Blacks, that is indeed a real observation, but IQ isn’t entirely genetic. The reason IQ scores are rising worldwide (the Flynn Effect) is due to improvements in environmental conditions: Fewer environmental pollutants—particularly lead and mercury, the removal of which is responsible for most of the reduction in crime in America over the last 20 yearsbetter nutrition, better education, less stress. Being stupid does not make you poor (or how would we explain Donald Trump?), but being poor absolutely does make you stupid. Combine that with the challenges and inconsistencies in cross-national IQ comparisons, and it’s pretty clear that the higher IQ scores in rich nations are an effect, not a cause, of their affluence. Likewise, the lower IQ scores of Black people in the US are entirely explained by their poorer living conditions, with no need for any genetic hypothesis—which would also be very difficult in the first place precisely because “Black” is such a weird genetic category.

Unfortunately, I don’t yet know exactly what it takes to change people’s concept of group identification. Obviously it can be done, for group identities change all the time, sometimes quite rapidly; but we simply don’t have good research on what causes those changes or how they might be affected by policy. That’s actually a major part of the experiment I’ve been trying to get funding to run since 2009, which I hope can now become my PhD thesis. All I can say is this: I’m working on it.