My fellow pro-growth/progress/abundance Up Wingers,

How much of your economic future is in your genes? How much of your kids? How much of America’s, for that matter?

Lots of folks in Silicon Valley certainly think DNA is destiny, or at least highly directional. The country’s tech elite are embracing embryo screening to engineer smarter offspring. That means spending up to $50,000 on genetic tests that claim to predict IQ alongside disease risks — all outlined in a Wall Street Journal story from August, “Inside Silicon Valley’s Growing Obsession With Having Smarter Babies.” Companies like Orchid Health, Nucleus Genomics, and Herasight offer polygenic (meaning traits influenced by many genes working together, not just one) scoring of embryos created through IVF, analyzing thousands of genetic variants.

The smart-baby movement, championed by tech sector figures including Elon Musk and Peter Thiel, reflects a) pronatalist anxieties about declining birthrates and b) fears that enhanced human intelligence is needed to manage artificial intelligence safely. Despite considerable scientific skepticism — current models explain only five to 10 percent of cognitive differences and might yield just three to four IQ points, the WSJ piece notes — demand is apparently surging among the digital denizens of the Bay Area.

Not that there are any other plausible options besides embryo selection and being picky about your mate. Most scientists reckon that boosting intelligence through direct genetic tinkering remains a distant prospect. IQ is influenced by thousands of genetic variants, each with tiny effects and entangled with environmental factors. This current reality means the dream of engineering cleverer kiddos isn’t a today thing.

(Then there’s this from a lengthy Washington Post piece from July, “Inside the Silicon Valley push to breed super-babies”: “Some critics see its polygenic scoring as veering toward a contemporary form of eugenics, enabling a world in which the rich leap even further ahead with super intelligence and superior health starting from birth.” Just putting that out there since not everyone is thrilled about the prospect of a “Gattaca stack” of pro-IQ interventions and its transhumanist implications.)

From sci-fi dreams to social science

Silicon Valley’s fascination with embryo screening reflects a speculative bet on sculpting future intelligence by people with a soft spot for science fiction. Meanwhile, economists are turning their attention to the more grounded question of how genetics already shapes economic outcomes. A new NBER working paper, “A Chip Off the Old Block? Genetics and the Intergenerational Transmission of Socioeconomic Status,” carefully wades into one of the thorniest questions in economics: How much of inequality is inherited biologically, rather than socially?

Its conclusions are provocative, as is always case when talking about genetics and human performance. TL;DR: Genes really do matter for education, income, and wealth. That, not only through what parents pass down biologically, but also through the environments they create. For policymakers, the lesson is nuanceed. Yes, genetics is a powerful anchor of inequality — but it’s hardly the whole story.

From the paper:

These findings reveal that a perturbation [in parental] genetics does not stop with them — it sends ripples across generations, shaping the lives of their descendants in the offspring generation and beyond. … Much of the concern over intergenerational persistence of socioeconomic status focuses on the perceived unfairness that an individual’s economic prospects depend on their socioeconomic background. Our results highlight a parallel, less-discussed source of inequality: children of parents with specific genetic variants also enjoy a head start.

The authors — Sjoerd van Alten (Vrije Universiteit Amsterdam), Silvia H. Barcellos (University of Wisconsin–Madison and NBER), Leandro Carvalho (University of Southern California), Titus J. Galama (University of Southern California), and Marina Aguiar Palma (FGV-Rio) — use Dutch tax records from 2006 to 2022 linked to genetic data from the Lifelines Biobank, a large population study in the northern Netherlands that tracks health, behavior, and genetics across three generations.

Together, those handy data sources provided the info needed to measure parental genetics with a special polygenic index, or PGI, geared toward educational attainment. (In this case, we’re talking about a single number that combines many tiny genetic influences to capture part of the inherited tendency to stay in school longer.)

The random nature of genetic transmission allows the researchers to isolate causal effects rather than simple correlations:

Humans have two copies of each genetic marker. During conception, each parent transmits only one of their two copies to their offspring, and the selection of which copy is transmitted occurs at random. … Once we control for the sum of the PGIs of an individual’s parents, the remaining variation in the individual’s PGI is effectively random. This independence allows us to isolate genetic effects from environmental influences.

The double helix of inequality

The findings here are pretty bracing.

Even small shifts in parents’ genes show up clearly in their children’s lives. For example, moving just 10 percent higher on the parental genetic score for education translates into a child staying in school about an extra month — not huge for one family, but very meaningful across an entire population.

What’s more, that same 10-percent bump pushes parents nearly a full rung higher on the income ladder and their children most of the way there too. And the effect doesn’t come only from biology. Roughly half is direct inheritance, but the rest is “genetic nurture.”

Parents with higher genetic scores for education also tend to pair off with partners who are also well-educated and better off. That doesn’t mean people are picking mates based on DNA — the study finds very little evidence of genetic “like attracts like.” Instead, it’s sorting on visible traits such as schooling and income. But the effect is similar: Two successful parents create both a richer environment for their kids and a higher chance of passing on advantages, which makes the gene-linked edge even stronger.

Another interesting finding: “More direct evidence of genetic nurture comes from studies showing that the PGIs of adoptive parents are positively associated with [socioeconomic status] outcomes of their adopted children — despite the absence of shared genetics.”

Linking genes to material success inevitably stirs old fears of determinism, of inequality cast in stone. But the study offers no such simple story. Biology matters, yet it works through social channels. After genes set the stage, performance is mediated by family resources, schools, and social institutions.

That conclusion ensures disappointment for absolutists. For those who insist poverty is solely the product of late capitalism’s cruelties, the evidence that DNA confers a head start will be unsettling. For those who believe inequality is fated by biology, the equal importance of “genetic nurture” will be just as irksome.

Yet if environment matters for social mobility — again, roughly half the intergenerational effect stems not from what parents pass on in chromosomes, but from the world they create for their children — that is encouraging since environments can be changed by public policy. From the paper: “Genetic effects do not represent destiny; rather, they depend on social, economic, and institutional contexts.”

The bottom line: Biology and policy are both implicated, yet neither is a done deal. Those IQ-obsessed techies might consider that the surer route to a smarter America runs through better schools and stronger neighborhoods, not just brainier embryos.