by Bryan Caplan
When I preach that “Parents count, too,” there’s a lot of push back. I feel like I’m on The Simpsons and Helen Lovejoy’s shouting, “Won’t somebody please think of the children?” However, if you not only think of the children but listen to them, you’ll end up following a lot of my advice. Kids may not realize that they can make themselves unhappy by demanding too much from their parents. Parents, however, should be mature enough to protect their kids from secondhand stress. When you can’t help your child with a sincere smile, it’s often kinder to gently refuse.
FROM HAPPIER PARENTS TO BIGGER FAMILIES
Parental unhappiness is not a complete myth. The average parent is slightly less happy than the average nonparent. My reaction is not to deny the facts but to ask, “Why settle for average?” Parents put an enormous amount of time and money into their children, and in terms of happiness, they almost break even. If you’re trying hard and almost succeeding, the natural response is not to give up but to rethink your strategy. With a little insight and creativity, parents can sharply improve their experience.
A dad once joked to me, “The first kid takes 99 percent of your free time; the second kid takes the remaining 1 percent.” The oneliner seems to affirm the inevitability of parental sacrifice but actually does the opposite. How can the second child be so much less work than the first? Because parents reallocate their time away from the firstborn to care for the baby. The implication: The elder child never really “required” 99 percent of their time in the first place. The parents could have given themselves a break all along, because much of their toil was superfluous.
If all my book does is make you a happier parent, I’ll be satisfied. Still, I want to push my luck—to convince you to be the happier parent of a larger family. The argument is simple: Once you adjust the kind of parent you plan to be, you should also reconsider the number of kids you want to have. When you weigh whether to have one more, you shouldn’t base your decision on the lifestyle of Today’s Typical Parent. You should base it on the lifestyle you’ve chosen for yourself. When you live by the philosophy that “Parents count, too,” you buy your kids at a hefty effort discount. Why not stock up?
Now it’s time to grapple with the strongest objection to my selfstyled “commonsense guide to happier parenting”: In the future, your children will pay the price for your lackadaisical attitude. We all know how important parenting is, right? Energetic parenting supposedly turns children into healthy, smart, successful, virtuous, and possibly even happy adults. When young adults fall short of this ideal, we round up the usual suspects—bad, lazy, or absent parents who failed to do their job.
From this perspective, a take-it-easy approach only seems better for parents. Letting your kids watch Saturday-morning cartoons while you sleep in feels pleasant at the time. When eighteen years of shortcuts turn your son into an unemployed dropout who spends his days playing video games in your basement, though, a single question will torment you: “What have I done?”
I will not respond to this objection by trotting out a bunch of studies claiming that hands-off parenting leads to independence or that video games build brain cells. I don’t claim to know the real way to mold your children into adults you can be proud of. My response is more modest, yet more radical: The best available evidence shows that large differences in upbringing have little effect on how kids turn out. While healthy, smart, happy, successful, virtuous parents tend to have matching offspring, the reason is largely nature, not nurture.
When I say “the best available evidence,” I’m not talking about a handful of studies that are slightly less bogus than the competition. The best available evidence on the nature-nurture question is excellent. Twin and adoption studies aren’t quite as good as controlled laboratory experiments, but many are close. Thousands of research papers have applied these methods to hundreds of controversial questions. They reach an amazing consensus about what counts for kids.
2
THE CASE AGAINST GUILT: A PARENT’S GUIDE TO BEHAVIORAL GENETICS
When I was just a little girl / I asked my mother, “What will I be?” / “Will I be pretty?” / “Will I be rich?” / Here’s what she said to me: / Que sera, sera / What- ever will be, will be; / The future’s not ours to see. / Que sera, sera.
—Doris Day, The Man Who Knew Too Much
KIDS BORN TODAY REQUIRE FOOD AND SHELTER, JUST AS THEY DID a hundred thousand years ago. Meeting these basic needs is far easier than it once was—we buy at the store rather than hunt in the wild. As we’ve gotten better at providing food and shelter, however, we’ve also upped our standards of good parenting. Modern parents feel obligated to make many extra credit investments in their children’s future. Their “free time” revolves around their children: preparing them, shuttling them around, and watching them from the bleachers.
Why do parents kill themselves, instead of taking my easy way out? Unlike a lot of expert recommendations, it is hard to deny that my approach would work as advertised. At least in the short run, parents would clearly be happier if they gave themselves a break. Moms’ and dads’ central objection is that if they cut corners, they risk their children’s future. Indeed, they often shudder when they hear my advice. Their heads fill with images of lazy parents fiddling while their oversized packs of barbaric children burn down Rome.
We’re going to see that these fears are mostly, if you’ll pardon the expression, old wives’ tales. You can do a lot less without risking your children’s future, because children are far more resilient than we realize. Once upon a time, nature versus nurture was a matter of opinion, but now there are hard answers: Nature wins, especially in the long run. If your child had grown up in a very different family—or if you had been a very different parent—he probably would have turned out about the same.
This may sound discouraging. No parent wants to hear that his sacrifices have been in vain. I insist, however, that the glass is more than half full. Do you think your kids will turn out all right? You probably should; most eventually do. Well, if I’m telling you the truth about nature and nurture, you don’t need to make great decisions to get kids you can be proud of. You don’t have to live up to the exhausting standards of the Supermom and Superdad next door. Instead, you can raise your kids in the way that feels comfortable for you, and stop worrying. They’ll still turn out fine.
HOW TO TELL NATURE FROM NURTURE
Patri Friedman is one of the most exciting characters I’ve ever met. He’s the grandson of Nobel Prize–winning economist Milton Friedman, known for his staunchly libertarian views, and the son of economist David Friedman, who makes father Milton look like a socialist. At Patri’s 2005 wedding, a year before Milton passed away, guests saw three generations of Friedmans side by side. All were short and hyper. All were brilliant, creative, and loved a good debate. None were religious. All were libertarians. All were obsessed with economics. Admittedly, only Milton and David became economics professors. But after working for Google’s prediction markets project, Patri decided to bring his sires’ libertarian economics to life by founding the Seasteading Institute, a think tank that explores the feasibility of floating city-states on the high seas.
What should we think about the Friedmans’ eerie family resemblances? We tend to see their physical similarity as hereditary. The first time you set your eyes on Patri, you’ll hail the power of the Friedman genes. Elfin Jew begat elfin Jew begat another elfin Jew. In contrast, we tend to see their psychological and behavioral similarity as proof of the power of parenting. The first time you argue with Patri, you’ll probably imagine that he spent decades learning the family business over the dinner table. Patri is brilliant and hyper, economistic and libertarian, because he was raised that way, right?
If you share these musings with Patri, however, he’ll disagree. His parents divorced when he was a baby, and his dad lived in another state. How then did he come to his distinctive outlook? Patri tells me he’s been this way as long as he can remember. He entered the family busin
ess long before he knew it was the family business.
Perhaps Patri understates his family’s influence. Once he was eight or so, he started spending summers with his dad. Perhaps people who knew about his Nobelist grandfather treated Patri in subtly different yet life-altering ways. Still, Patri’s story raises a red flag: We might draw the line between nature and nurture in the wrong place. What makes us so sure that we’re good at telling the two apart?
The naive reaction to these doubts is to carefully study lots of families. Alas, you can’t get anywhere on the nature-nurture issue merely by looking at typical families, because the typical family seamlessly blends biology and upbringing. We normally share half of our siblings’ genes, plus a childhood in the same home. As long as these two treatments are woven together, we’ll never figure out what’s going on. Intelligent bystanders’ reaction is usually to split the difference and decree, “Both nature and nurture are important,” or else declare the question insoluble.
Fortunately, active researchers in this area aren’t so quick to admit defeat. After they concede that nature and nurture seamlessly go together in the typical family, they retort that not all families are typical . The secret to unraveling the nature-nurture mystery is to study special kinds of families where there is a clear seam—or even a complete separation—between biology and parenting. From this standpoint, two kinds of families are special: Families that adopt, and families with twins.
We can clearly learn a lot by looking at families that adopt. When a couple raises the child of a perfect stranger from birth, any family resemblance is probably due to nurture. If you’ve never even met your birth parents but resemble them anyway, the reason is probably nature.
What about families with twins? At first glance, they have the same problem as “regular” families—they seamlessly blend biology and upbringing, making it impossible to tell the two apart. But there are two kinds of twins: identical and fraternal. Identical twins share all of their genes. They usually look so similar that strangers have trouble telling who’s who. When people ask me how to tell my identical twin sons apart, I point out that one has a barely visible birthmark on his chin. Fraternal twins share only half of their genes—no more than ordinary siblings. So if identical twins resemble each other more than fraternal twins, the reason is probably nature.
Not good enough for you? We can go to the next level by looking at twins who were separated and raised by different families. If identical twins raised apart are more similar than fraternal twins raised apart, the reason almost has to be nature. If twins raised together are more similar than twins raised apart, the reason almost has to be nurture.
A few decades ago, twin and adoption methods were little more than neat ideas. Since then, hundreds of researchers have taken these neat ideas and run with them. The result is a new discipline—behavioral genetics—and an imposing stack of studies that use twin and adoption methods to settle the nature-nurture debate, trait by trait.
What do these studies reveal? Most expect the middle-of-the-road answer that both nature and nurture are important. Indeed, most have trouble believing anything else. But believe it or not, twin and adoption studies do not support the middle-of-the-road answer. Identical twins are much more similar than fraternal twins—even when separated at birth—and their similarity often increases as they age. When adopted children are young, they moderately resemble their adopted family. By the time adoptees reach adulthood, however, this resemblance largely fades away. Taken together, there’s a striking lesson: Nature matters a lot more than nurture, especially in the long run.
NATURE VERSUS NURTURE: CLARIFYING THE QUESTION
Twin and adoption studies are powerful microscopes on the human condition. Before we start looking through the microscope, however, let’s take the device apart and see how it works.
EXPLAINING VARIATION
It is easy to devise examples where nurture matters tremendously. If you raise a child in a closet and make sure he never hears a word, he won’t learn how to speak. It is equally easy to devise examples where nature is all powerful. If a child gets two copies of the gene for Tay-Sachs disease, he’ll almost surely die by the age of five. How can nature or nurture “matter more” if either can make all the difference in the world?
Researchers handle this issue by focusing on what’s important in practice, instead of mere hypotheticals. They don’t ask, “What could make people different from each other?” They ask, “What does make people different from each other?” They don’t ask, “How would this child have turned out if he were raised by wolves?” They ask, “How would this child have turned out if he were raised by one of the other families we interviewed?” If an adoption study concludes that nurture doesn’t matter for height, this means that existing parenting differences do not affect kids’ height. If a twin study, similarly, reports that upbringing doesn’t affect income after age thirty, this doesn’t mean that your dad can’t hire you for double your market value, merely that such nepotism is vanishingly rare in the real world.
Nurture has two distinct ways not to matter. One is simple; the other is subtle. The simple way is when height is completely out of parents’ control. If nothing in the parental toolkit affects height, we won’t find a nurture effect. The subtle way is when all parents affect height to the same degree. If every parent takes actions that raise her children’s height by four inches, differences in parenting won’t explain why some kids are taller than others. The same distinction applies if you say that nurture doesn’t matter much. It could mean that parents only have small effects; it could mean that parents have similar effects.
Notice: If your goal is to understand differences that we actually observe, it’s important to specify where we actually look. Most twin and adoption studies focus on people raised in advanced Western countries in modern times. So if a study finds that nurture doesn’t matter for height, this tells us that mixing up two babies at an American or a Swedish hospital will leave their adult stature unchanged. If a mix-up sent a Haitian baby to food-rich America, and an American baby to hungry Haiti, the effect on height could be massive.
From a social scientist’s point of view, this is an important distinction. You can’t look at families in the United States or Sweden, conclude that almost all are good enough to allow children to flourish, then infer the same about families in Haiti. From a parent’s point of view, however, this distinction is rarely relevant. If you’re reading this book, you probably live in the First World—or at least enjoy a First World standard of living. When you decide what kind of parent to be, you aren’t wondering whether you should emigrate to Haiti to raise your children in dire poverty. Instead, you’re weighing the pros and cons of the parenting styles used by people like you. If you discover that these styles are equally good for kids, you have the information you need.
NURTURE AND ENVIRONMENT ARE NOT THE SAME
No two people have exactly the same environment. Two children who live under one roof have different teachers and friends. They watch different TV programs and eat different foods. One has the top bunk, the other has the bottom bunk. One gets a spanking, the other gets a bedtime story. Most, but not all, eventually leave their childhood home. How then can researchers say that two kids were nurtured in the same way?
The answer is that researchers equate “nurtured in the same way” with “were raised by the same people.” If parents’ income, education, marital status, parenting philosophy, religion, school district, or favorite color affects their children, it counts as nurture. What doesn’t count as nurture? Any feature of children’s environment that varies despite the fact that they were raised by the same people. Researchers call such features “unique environment” or “nonshared environment,” but you could just as well say “none of the above.” Anything from peers, germs, and television to parental favoritism, dumb luck, and free will could qualify as unique environment.
Unique environment is a provably powerful force. My first two children share a
ll their genes. They’ve lived with my wife and me since their birth. Yet they’re different. One twin is more argumentative, the other eager to please; one focuses on following the rules, the other on making friends. If we took the nature-nurture debate literally, the individuality of my sons—or any identical twins raised together—would be impossible. The solution to this paradox: Instead of picturing a two-way race between nature and nurture, picture a three-way race between nature (also known as heredity and genes), nurture (also known as upbringing, family, parents, and shared family environment), and unique environment (also known as nonshared environment and none of the above). If you’re studying height, for example, there are three questions to ask. First: How much height variation is due to genetic differences? Second: How much is due to differences in family environment? Third: How much is due to everything else? The fact that genes don’t explain everything does not imply that family environment explains the rest.
NATURE AND NURTURE: DIRECT VERSUS INDIRECT EFFECTS
Twin and adoption studies are great ways to distinguish nature from nurture. However, they rarely help us distinguish different kinds of nature, or different kinds of nurture. Instead, they bundle all direct and indirect effects together. If researchers report that genes affect income, for example, the reason might be that genes matter for intelligence, and intelligence matters for income. It could just as easily mean that genes matter for looks, and looks matter for income. There doesn’t need to be an “income gene.” Similarly, when researchers report that nurture matters for religion, the reason might be that parents instill religious values; yet it could just as easily mean that parents control religious education, which in turn instills religious values.
