The Genetics of Evil: Are People Born Bad? - Dr Kathryn Paige Harden - #1066

What happened after your last book came out? It felt like you were trying to free people from confusion, yet others tried to pin a false story on you, and the sting comes when you fear the crowd might buy it.

Readers wrote with gratitude about finally understanding why they differ from family or how genetics shaped choices about kids, which I loved, but some academics cast me as a villain to boost their own points and it was disorienting to see words on the page twisted. My dad, a former Navy pilot, told me you take the most fire when you’re over the target, and genetics clearly hits real-life nerves.

You helped run a four million person study—what did you find?

We pooled DNA from biobanks and 23andMe to find variants tied to seven rule-breaking or disinhibited behaviors and asked whether shared genes underlie general risk-taking. The same liability spans life stages, and human behavior varies wildly, like sexual partners ranging from none to nearly a hundred.

Before we get spicy, what are the evolutionary roots of aggression and impulsivity?

Humans likely self-domesticated toward cooperation and self-control, yet societies also reward some risk and norm-bending to drive innovation. For instance, among resourced young men, mild teenage delinquency predicted later entrepreneurial success, which shows the ongoing tension between conformity and deviance.

There’s survivorship bias in the bold bets, but it still pays for some, even as our species tightened self-regulation.

We carry strong empathy and foresight, yet traits sit on spectra where extremes harm and moderate levels can help. People high on schizophrenia-related variants who aren’t ill show up more in creative fields, and I think some disinhibition works the same way.

What about psychedelics and psychosis risk?

Family histories of schizophrenia or bipolar disorder heighten risks from cannabis and psychedelics, with first episodes clustering from mid-teens to late twenties, so I tell my kids to wait until after thirty. Psychedelics can shake rigid patterns in midlife, but your twenties are already volatile, so more disruption isn’t always wise.

Is wrongdoing freely chosen, or are we born leaning toward transgression?

We’re shaped by luck—our genomes and early choices steer who does the choosing—so the abstract free will debate helps less than asking how science should inform responsibility, mercy, and safety. Our intuitions shift when causes differ, like seizures versus panic versus harsh upbringings, and courts and relationships grapple with that messiness.

I agree; acting as if we have agency is useful, then we tune the variables inside that sandbox.

Even if determinism is true in some grand sense, jurors and loved ones still need practical ways to assign responsibility and move forward together.

How heritable is anti-social behavior?

Persistent rule-violation in childhood is highly heritable, especially when paired with callous-unemotional traits that blunt guilt and empathy, whereas kids acting out from trauma show lower heritability and more environmental causation. The callous-unemotional subtype is the toughest to treat in child psychiatry.

How do people usually respond to these kids, and what lens would you offer instead?

Adults often recoil or clamp down with harsh control, but these children are unusually insensitive to punishment and more responsive to rewards and connection. Cranking up consequences can sever the very bonds that help them learn, creating a vicious spiral.

What happens as this carries into adulthood?

We rightly feel outrage at adult harm, but many pathways trace back to development, which is why we flail with teenage shooters—sometimes trying kids as adults while charging parents—which reveals deep moral confusion.

When do we say someone is culpable?

Culpability slides by person and age, while the law draws hard lines, and child soldiers show the need for rituals that both name the harms done to them and ask them to take responsibility for harms they caused.

And addiction?

Recovery frameworks like AA hold two truths at once—powerlessness over a substance and a daily commitment to change—and that both-and stance is a model we struggle to extend to violence because of its victims.

Do genes shape agency itself?

Everything we do is embodied, including willpower and even belief in free will, which shows heritability, and real change often requires community support, not just grit.

Twin work reminds me there’s no clean carve-out between body and spirit here—it’s genotype all the way down—yet we still live meaningful, value-driven lives within that reality.

These topics are taboo; is heritability different by sex?

The same liabilities operate in boys and girls, though men sit higher on average for aggression and risk, and we’re now probing X-chromosome effects, including a rare MAOA mutation in one family that drove extreme male violence while carrier sisters functioned typically.

I separate accountability from punishment: we must protect the public and enforce rules, but the American default to retribution and warehousing people doesn’t deter violence and inflicts needless suffering. I don’t think anyone deserves to suffer, even as we set firm boundaries.

Should courts treat people differently with this science in mind?

We already present mitigation at sentencing, but genetic evidence often makes jurors harsher because they see future danger, while environmental stories tend to soften blame; neither approach has fixed our outcomes because prisons rarely rehabilitate.

So people punish more when they think the cause is in the blood, since risk feels baked in.

That’s genetic essentialism—switching from “caused by genes” to “you are your genes”—and once someone is seen as bad to the core, sympathy collapses.

Where does retribution come from?

It’s a cooperation-enforcement instinct that lights up reward circuits when we see defectors punished, and people will even pay to punish freeloaders in lab games.

This explains dehumanization, moral panics, and why we guard our reputations—people enjoy punishing and may pay to see it.

Empathy hurts, so we seek reasons to flip pain into pleasure by declaring someone deserving, which is why media dredges victims’ pasts to justify harm and dim our compassion.

There’s also virtue display in calling out defectors; your status rises as theirs falls.

American culture serves empty-calorie vengeance like ultra-processed sugar, whereas Norway’s response to Breivik chose safety and dignity over maximal cruelty, keeping humanity in view even for the worst acts.

Do such offenders retain any humanity, and isn’t leniency weak?

Denying their humanity corrodes ours, and while punishment signals the worth of victims, no penalty can satisfy what was taken, so we should balance protection, rehabilitation, and restrained retribution.

Without a full genetic lens, we misread who chose and who was pushed.

A Texas inmate wrote asking if kids go bad from nature or nurture, but beneath that is a plea for blame, hope, and a new story about self, which science alone can’t settle yet can inform.

We rarely ask the same hard questions when we do something surprisingly good.

Sometimes the best writing feels like it came through me, not from me.

What’s real and what’s hype about epigenetics?

Epigenetics are chemical marks that tune how genes are read, and while transgenerational inheritance in humans is debated, we can see DNA methylation in children reflect early adversity long before illness appears. I focus on those early biological signatures rather than grand claims that epigenetics explains everything.

How plastic is it?

Childhood is peak plasticity, with epigenetic patterns more changeable early and more stable later, so interventions still help in adulthood but the first decade is the most malleable window.

The Dutch Hunger Winter shows how timing in pregnancy matters; deprivation, especially in mid‑gestation, tracks into children’s and even grandchildren’s health and behavior.

We’re studying an unconditional cash transfer to low‑income moms, and while I can’t share results yet, moms with more money breastfed longer, delayed daycare, and improved kids’ nutrition—behavioral shifts that still land in the epigenetic lane because the genotype stays the same while biology and behavior change.

On epigenetic age clocks, think methylation patterns rather than telomeres, and yes, even the Kardashians dabbled, hilariously butchering Steve Horvath’s name; I’d put that clip in every keynote if I were him.

What did motherhood teach you about luck?

Parenthood is the boldest bet there is; kids aren’t copies, they’re new combinations, and siblings can be wildly different, so my job is to meet the person I got, not mold a project.

I support reproductive autonomy and see clear upsides to screening when there’s a known disorder, but I worry about overselling polygenic predictions and about how turning chance into choice shifts social judgments—like the way near‑universal Down syndrome screening in some countries reframed disability as a parental decision rather than a shared responsibility.

IVF already involves picking embryos for viability, so adding a dashboard feels incremental; given stories like Ethan Strauss on parenting a son with autism, why does elective selection still unsettle you?

I feel a real tension between reducing suffering for a child and family and honoring the relationship with a person who isn’t mine to perfect; both values matter, and they collide in ways I can’t neatly resolve.

Isn’t it kinder to select for a child more ‘fit’ for modern life?

Once you leave single‑gene diseases, traits trade off; alleles tied to autism overlap with education, and risk‑taking can fuel creativity as well as crime, so a world bred for max compliance would be safe and suffocating.

Societies benefit from variation even if families bear the costs, which is why I favor pluralism over top‑down reproductive rules, especially in a country already divided on bodily autonomy.

What about the ‘crumbling genome’ idea—medicine relaxes selection, mutations pile up, and embryo selection becomes a fix?

Niche‑building always reshapes selection; there are still pressures, just different ones, and evolution isn’t aiming at a universal ‘better’—fitness is environmental, which is why even hearing loss can be embraced in Deaf culture, and why past eugenic logic rings alarm bells.

Modern norms curb male aggression and dominance; does that impose a bigger self‑control tax on men?

At the extremes, sex differences show up, but most men and women overlap; I’d redesign school for boys’ development—more movement, mixed ages, real responsibility—rather than argue over fairness in the abstract.

Data won’t soothe how many young men feel unmoored; the better move is to build institutions that help both sexes thrive instead of treating progress as zero‑sum.

As a geneticist, how do you see looks‑maxing?

It’s oddly self‑defeating when hormone cycles blunt fertility, and it also confuses signals with success; we evolved to pair up and raise kids, which is about attachment more than aesthetics.

Some guys say it’s really about competing with other men, where formidability beats raw looks.

From my own life, credentials and income weren’t decisive; competence and contribution were, so I’d tell men to build capabilities you can bring to a partner and a community, not just sharper jawlines.

Online life rewards the visual flex, not quiet competence.

I hear that in class when students admit they’ve never been to a party; if connection moves to screens, surface signals dominate, but they won’t help you bond or sustain a life together.

This was a blast—wide‑ranging and fun. My new book, Original Sin, lands in the United States in March and the United Kingdom in April; it weaves genetics, addiction, antisocial behavior, free will, forgiveness, and a personal prologue about living in a body. If those themes speak to you, I’d love for you to read it.

We did it. If you want a friendly place to start reading, grab my Modern Wisdom list of one hundred punchy, memorable books with short notes and buy links, all free at chriswillx.com slash books.