Genetics & Dax: A Thoughtful Account of How We Chose the Best Possible Start
What follows is written from Arthur's perspective, detailing the rationale and process behind our genetic screening choices. We believe in transparency and sharing knowledge, especially on topics as complex and sensitive as this one. Our goal was to make informed, ethical decisions that prioritize our future child's health and well-being.
Both Genetics and Developmental Environment Matter
From the very beginning of this journey, I knew that both genetics and environment would profoundly shape who our child becomes. Development matters enormously: Prenatal health, nutrition, emotional stability, early education, and the overall texture of a child's life all contribute to their long-term flourishing. Jessie, our surrogate, was selected with extraordinary care for exactly these reasons: Her commitment to health, her consistency with supplements, her emotional equanimity, and her alignment with the lifestyle choices we value made her the best possible partner in creating the optimal gestational environment.
But genetics matter, too, more than most people realize or are comfortable acknowledging. Research synthesized in books like Blueprint: How DNA Makes Us Who We Are by Robert Plomin make a compelling case that many psychological and behavioral traits we used to attribute primarily to parenting or environment—intelligence, personality, temperament, even life satisfaction—are substantially heritable. Heck, we even likely have the causality wrong about kids who are read to and their later love of reading. (The data more strongly favors the explanation that children's inherited love of being read to is what encourages their parents to read to them.) Don't get me wrong—environment still matters profoundly, but its influence tends to be less systematic, less predictable, and often less controllable.
The way I see it, environment is the construction crew, and genes are the blueprint. You can't build a skyscraper with the blueprint for a shack, but even the best blueprint still needs builders who care, who pay attention, and who shape the outcome with love and intention. So our approach has always been to optimize both. Choose the best possible genetic starting point, and then build the best possible environment on top of it.
Uncontroversial, Standard Practical Steps: Egg Donor Selection, Early Genetic Screening, and PGT-A
Before we ever reached embryo selection, we took the standard and essential steps to ensure that we were working with the best possible ingredients.
Egg Donor Selection (Phenotype & Family History)
In Brit, I found an egg donor with exceptional manifested traits: intelligence, creativity, emotional warmth, physical health, and a strong track record of achievement (to say nothing of extreme beauty). These qualities rarely arise without some significant genetic endowment, so while nothing is guaranteed, there's good reason to infer that these advantages are partially rooted in heritable traits. That made her an extraordinary match.
We each did 23andMe testing and independently reviewed the results, mostly to cross-check for major health-risk alleles, recessive disease carrier status, and ancestry-related factors. We also compared family histories to ensure alignment in health trajectories and to reduce risks that otherwise wouldn't show up in test results.
Clinic Genetic Screening
Once Brit and I agreed to move forward in combining our genetics, the fertility clinic conducted its own extensive genetic screening panel. This confirmed the absence of major monogenic disease risks and provided another layer of validation that our donor selection was grounded in good science, not wishful thinking.
PGT-A Testing
After fertilization, we performed PGT-A testing on all embryos to detect chromosomal abnormalities. Out of twelve that developed well morphologically, six were chromosomally viable: three euploid and three low-mosaic. This is standard best practice, but it only screens for the most coarse-grained issues: missing or extra chromosomes. It doesn't tell you anything about long-term disease risk, cognition, or lifespan-related traits. That's where the next step came in.
Using Herasight's Technology: How It Works and How We Used It
PGT-A tells you which embryos can lead to a pregnancy. Herasight tells you which embryos are likely to lead to the best long-term outcomes. Their technology reconstructs 98-99% of each embryo's genome using a combination of biological parents' and grandparents' full-genome sequencing. In our case, that included my, Brit's, and my father's full genomes.
This high-resolution imputation feeds into rigorously validated polygenic models for numerous traits, from lifespan and disease susceptibility to cognitive potential and height. These models are derived from massive GWAS datasets and tested on real siblings to confirm predictive accuracy.
The Tradeoffs I Expected (and the Ones I Didn't)
Going into the process, I joked that I'd probably face a humorous tradeoff: The embryo with the highest predicted IQ probably wouldn't have the highest predicted height and vice versa. I wondered how many IQ points I'd be willing to trade for how many inches of height. In some ways, that turned out to be partially true: There were mild tradeoffs along those dimensions. But they were so minor that other factors took precedence.
Ultimately, I chose the embryo with the highest Longevity Index, which synthesizes the predicted impact of many health-related polygenic traits into a single metric approximating lifespan and healthspan. This embryo also had excellent predicted cognitive ability and respectable predicted height. It wasn't unequivocally the "best" in every category, but it had the best overall combination of traits.
It was an integrated, rational decision: Aim for the longest, healthiest life possible, while also supporting cognitive flourishing and other positive traits.
And the intermediate result speaks for itself: The embryo transfer succeeded on the first attempt, and we're now expecting a healthy baby boy—Dax—in January.
The Psychological Catch-22 of Knowing This Technology Exists
This part surprised me. I've always been someone who wants more information rather than less, but I quickly realized that the more you know, the more complicated parenting psychology becomes.
On one hand, knowing the predicted strengths of your future child creates a risk of forming expectations, conscious or subconscious, that could accidentally become pressure. Reflecting on my own childhood, I was lucky: My parents had high expectations, but it manifested more as regarding excellence as a default, not as a demand or as a burdensome pressure. But I don't think that happened with conscious intent, so it's something I'm wanting to be mindful about here.
On the other hand, not using the technology creates a different kind of psychological hazard: the potential for regret or second-guessing. If Dax were to later struggle with a preventable health condition, or if some cognitive deficiencies (however mild) became evident—or even imagined—I know I would have wondered whether things could have been different if I had simply used the information available to me to select a different embryo.
Ultimately, I realized that the healthiest path was to embrace the information, make the most responsible decision possible, and then cultivate an environment where excellence feels normal, not demanded, where potential is nurtured, where love is not conditional on achievement, even if predictions turn out wrong in either direction.
This is the approach in a nutshell: Use data wisely, and parent with love.
Note: We are not shy about sharing some of Herasight's results for Dax, but the internet is forever, and when Dax is old enough to read all about his creation, the last thing I'd want is for him to think he needs to live up to the predictions of a model. And for things like IQ, I actually have a rather dim view of IQ as a meaningful measure in itself, but since it's the best tool we have for quantifying cognitive powers, it's what we had to use to rank the embryos along the dimension of cognitive potential.
The Philosophical Dimension: Eugenics, Ethics, and Responsibility
You can't have expected a website created by Arthur to not involve some more serious philosophizing, right? Here's the part that people either find fascinating or terrifying, but almost never understand in a nuanced way.
This Is Eugenics (Just not the Kind Most People Fear)
When people hear the word "eugenics", they almost always immediately recall historical atrocities or grim sci-fi dystopias. That reaction is understandable, but it obscures the reality: Humans have always engaged in eugenics in the literal sense of selecting among natural variation. First unconsciously (mate selection based on health, beauty, intelligence, and even confidence), and now consciously through donor selection and prenatal screening.
What Herasight offers is simply a more scientific, transparent, and data-rich version of what we've been doing in coarse form since time immemorial. And unlike the dark chapters of the past, this technology is voluntary, individual, and compassion-driven.
Avoiding "Pretty but Frail"
Traditional donor selection puts an enormous emphasis on superficial phenotypes—especially beauty—which has no meaningful correlation with long-term health or cognitive traits. (Heck, looking through donor profiles feels like swiping through Tinder profiles.) It's actually biased toward the "beautiful but frail" problem that some people worry Herasight would magnify. But high-resolution genomic prediction actually corrects that bias. It helps parents choose based on what actually matters for well-being.
The irony is that people worry that this technology will lead to "designer babies" focused on superficial traits, selecting for appearance at the expense of health and cognitive potential, when in reality, it helps avoid that problem. In my view, I think it's more likely that parents willing to invest in this technology will prioritize health and cognitive traits over superficial ones, because they're motivated to give their children the best possible start in life. (And don't get me wrong—beauty is important, but it has to be integrated in the full context of factors that matter for flourishing, wellbeing, and prosperity.)
Primary Responsibility to My Child
My first responsibility is to my child: to reduce preventable suffering, increase his chances of a long and healthy life, and support his ability to thrive. This technology helps me fulfill that responsibility. If I can reduce his risk of heart disease, cancer, diabetes, osteoporosis, mental illness—and simultaneously support cognitive flourishing—why would I not?
Side Note: Selection Versus Enhancement
It's important to distinguish between selecting among naturally occurring genetic variations (which is what we did) and attempting to "enhance" traits beyond possible genetic recombinations of the parents / genetic donors or even the normal human range (which this technology does not do). We're choosing the best possible version of a human being within the existing spectrum, not creating superhumans or alter fundamental aspects of identity. But if we could, say, CRISPR our baby to be taller or smarter or have superior visual acuity or kinesthetic sense in a way that's safe and well understood, I would still argue that, as is practically possible, it is a profoundly moral choice, just as providing a stimulating developmental environment enhances cognitive potential. Retreating to "Oh, but it's only selection, not genetic engineering." is a cowardly cop out.
Positive Externalities and the Zero-Sum Fallacy
Healthier, smarter, longer-lived populations benefit everyone, whether through selection or affirmative engineering, whether directly or indirectly. These traits correlate with greater innovation, greater wealth production, lower violence, stronger cooperation, and higher societal prosperity. This isn't a zero-sum world. One person's gain doesn't diminish another's.
People often fear that if someone else's child is healthier or smarter, their own child will be left behind. But human interests are profoundly non-zero-sum. We all benefit when the people around us have greater capacity, fewer limitations, and more to contribute. Raising the floor of human capability lifts everyone over time. The same concern arises in absurd arguments that reading to your child supposedly gives them an "unfair advantage" over children whose parents don't read to them, yet no reasonable person believes we should withhold books or bedtime stories in the name of fairness. Giving your child a better start isn't an act of aggression against or sabotage of others; It's simply fulfilling your responsibility as a parent to help them flourish.
What About People with Traits We Select Against?
Selecting an embryo with lower disease risk or higher cognitive potential does not imply that people who currently live with diseases or lower cognitive skill are diminished in value. Every person is an individual with unique values to contribute, according to the scope and scale of his abilities and ambitions. They may not be able to compete as well in some realms, but may out-compete others in other realms—or perhaps not—but in either event, it's not a reflection of their moral worth or standing, which are a function of character, not success in a competitive marketplace. Preventing future suffering is not the same as devaluing existing lives, any more than vaccinating against polio devalues people who had polio.
Addressing Gattaca Concerns
The dystopian fear is that society will become rigidly stratified by genetics. But that's a choice people in a society make, not an inevitability of technology. We already live in a world where traits differ widely, yet we (or at least the enlightened among us) manage to respect one another as individuals with unique contributions.
Early Adoption and Future Access
Like every transformative technology—IVF, antibiotics, smartphones—this began expensive and will become affordable. Early adopters are not hoarding advantages; they are accelerating the path toward widespread accessibility.
Conclusion
This technology is about compassion, responsibility, and honesty. It helps bring better lives into the world. That's something to welcome, not fear.