Sculptures by Sun-Rae Kim, part of a series called “Tscho-Young Nina’s Friends.” (Photo by Marla Aufmuth)

The Children You Could Have Produced Instead

Technology will dramatically increase the choices that parents can make about their offspring. But having too many options can be a bad thing.

I f you haven’t heard of embryo freezing, you should know that hundreds of thousands of people around you have been booted up from cold storage. They were immobilized at -196 degrees Celsius, sometimes for years, before they were thawed out and injected into a warm womb and they grew into a person.

Why do people freeze embryos? Fertility problems are the most common reason. By producing a surfeit of high-quality embryos through in-vitro fertilization and freezing them, one has “backups” and doesn’t have to start the process from scratch. And there are other reasons. Imagine you’re in the Army and about to go off to a war, and facing death inspires you to leave the possibility of babies with your partner. Or imagine you’re a couple with big careers that can’t be put on hold, and you want to stop the clock of your youthful genetics.

Embryo freezing has become increasingly popular; among other factors, it beats egg freezing. Few eggs survive freezing and thawing, mostly because of ice crystals — but embryos that have developed for a few days are significantly larger and tougher. Some parents have returned after more than a decade, thawed an embryo, and given birth to a perfectly healthy baby. It is thought that an embryo living in a liquid nitrogen world could be viable indefinitely. They are dormant possibility.

This reproductive technology is a triumph of science, but it has the potential to revise the typical sequences of parenthood: what if a couple freezes their embryos, and then “has” their child when they’re 70 years old, after doing everything they’ve wanted to do? And because I am a neuroscientist, embryo freezing makes me wonder about the issue of regret.

Say you have eight frozen embryos. You can use genetic testing to discover what diseases are expected in each embryo, and then select the one with the fewest health risks. This is great news for your child’s future. But there’s no real reason to stop there: after all, genetic testing grows more discerning each year. Which eye color would you like? How tall is each embryo expected to be? Which one will grow into the most muscular athlete? What will each embryo look like a few decades from now — and why shouldn’t you choose the most attractive one? All those options will give us more choice about our children than any previous generation ever dreamt.

That’s great, right? Maybe not. Put aside the concern that biological diversity will decrease as certain traits win out; instead, I want to address a psychological point. Parents generally have operated by a simple principle: we get the kids we get. They are the cards we’re dealt.

But in the near future, many parents will be able to say “I choose number 5” instead of “I choose number 7.” Parental brains will wrestle with questions they have never before faced in reproduction. Their children will share a bedroom with the what-if ghosts of the other children that could have taken his or her place.

(Photo by Marla Aufmuth)

So while choosing embryos seems like a good move for lowering the disease burden of the next generation, it promises to alter the psychology of parenting. How? Because of what’s sometimes called the paradox of choice: the more options you have, the less satisfied you’ll be. This has been demonstrated in countless scenarios. Imagine you enter a store that offers dozens of flavors of ice cream. After you’ve made your choice, you’ll enjoy your cone — but it turns out you would have enjoyed the same one even more if there were fewer choices, or no choice at all. This same effect is seen in studies from appliances to cars to mates.

Embryo choosing, therefore, offers a new opportunity for regret: a disappointment about active choices we have made (“I’ll choose number 3”) rather than the single, passive outcome we’re used to (“here’s your new baby!”). When your child throws a temper tantrum, lying down in the store aisle and kicking the floor, a thought may flit through your consciousness: what if I had chosen embryo number 4 instead? Let’s be clear that embryo number 4 would not be free of tantrums. But the brain’s capacity to simulate what ifs would set you wondering.

Or say you selected embryo 5, believing it was free of genetic risk — only to later discover a problem that was undetectable at the time. And embryo 2, which you passed over, would have avoided this outcome … had you only chosen differently.

The more options you have, the less satisfied you’ll be.

Why does having more choice lead to more regret? It’s because the brain chronically simulates possible futures. You can’t help this; it happens under the hood, without your awareness. The brain doesn’t live in real time: it constantly simulates from what-is to what-could-be. And it spends much of its time simulating what-could-have-been: the world that would have existed had you made different choices. Such fictive outcomes are compared against actual outcomes — and the difference is experienced as regret or relief. This is one way we learn: we use the signals of regret and relief to update our models of the world, and this helps us navigate our choices the next time a similar situation arises.

In the 1950s, psychologist Herbert Simon pointed out that many of us act as “maximizers” — that is, we want to make sure we always make the best possible choice. Unfortunately, as the number of options increases, it becomes ever more difficult to know that we’ve made the optimal pick. It is theorized that much of modern anxiety comes from the increased opportunities for selection, at the cost of happiness.

When it comes to offspring, we have always had a simplicity born of choicelessness. Now, more and more couples will opt out of that. This is not to say we shouldn’t build more choice into our lives; in this case, it will allow us to birth generations with less disease. But when things that were formerly out of our control become within our control, we’ll have to be poised for a somewhat different emotional world: one with the peculiar juxtaposition of more healthy, beautiful children, and more parental remorse.

David Eagleman is a neuroscientist at Stanford University. He is the author of the bestsellers Sum and Incognito, and the creator of the PBS series The Brain.