Kian Sadeghi: Genetic influence on IQ is 50%, the ethical complexities of embryo selection, and the historical dangers of eugenics | Tucker Carlson

Genetic testing in IVF sparks debate over ethics and the balance between science and parental choice.

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Add us on Google by Editorial Team Apr. 14, 2026

Key takeaways

• Genetic influence on traits can be assessed through twin studies, which compare identical twins raised in different environments.
• IQ is about 50% genetic, but it’s one of over 2,000 factors considered in genetic assessments.
• Selecting embryos involves reading DNA, not editing it, distinguishing it from gene editing.
• Genetics plays a significant role in societal traits, challenging the notion that environment is the sole factor.
• Eugenics aimed to control populations without a foundational understanding of genetics.
• Forced sterilizations are an evil manifestation of eugenics, but the ideology extends beyond that practice.
• The concept of a “best embryo” in IVF is misguided, as virtue is independent of biological characteristics.
• Parents’ choices in embryo selection are based on personal preferences rather than objective measures of virtue.
• There is a strong genetic basis for schizophrenia.
• The decision to screen embryos for genetic conditions should rest with the parents.
• Genetic testing in IVF involves complex ethical considerations and personal values.
• The historical context of eugenics shows its separation from legitimate genetic science.
• Understanding genetic influence requires acknowledging both genetic and environmental factors.

Guest intro

Kian Sadeghi is the founder and CEO of Nucleus Genomics, a genetic testing company that screens embryos for disease and enables parents to select traits like height, IQ, and personality. A Thiel Fellow and University of Pennsylvania computational biology dropout, he founded the company in 2021 after raising over $32 million from investors including Founders Fund, Seven Seven Six, and Samsung Next.

The role of twin studies in genetic research

• Twin studies provide a mechanism to measure genetic influence on traits.

• So using twin studies you can actually get measurements of things from diseases right like cancers and diabetes and alzheimer’s as mentioned to things like height or iq or bmi etcetera.

  — Kian Sadeghi

• These studies compare identical twins raised in different environments.
• Twin studies show that IQ is about 50% genetic.
• IQ is just one of over 2,000 factors that genetic assessments consider.
• Understanding twin studies is fundamental to genetic research discussions.
• Genetic influence on traits is multifactorial, involving both genes and environment.
• Twin studies challenge the notion that environment is the sole factor in trait development.

Genetic testing vs. gene editing in reproductive technology

• Embryo selection involves reading DNA, not editing it.

• So you’re actually not changing dna this is not gene editing you’re not changing dna you’re not making like an embryo’s dna better you’re basically reading the embryo’s dna that you have.

  — Kian Sadeghi

• Genetic testing is distinct from gene editing, which involves altering DNA.
• The process focuses on understanding existing genetic information.
• This distinction is crucial for informed discussions on reproductive technology.
• Genetic testing allows for informed parental choices without altering the embryo.
• The ethical implications differ significantly between testing and editing.
• Understanding this distinction helps clarify misconceptions about genetic selection.

The impact of genetics on societal traits

• Genetics plays a significant role in various societal traits.

• It seems like that debate is over… genexx plays a big role… when people think about like height or cancers… those conditions are basically deterministic in nature.

  — Kian Sadeghi

• This challenges the historical debate on nature vs. nurture.
• Genetic influence is critical in discussions on social policy.
• Understanding genetic impact helps address societal issues more effectively.
• Traits like height and certain diseases have a deterministic genetic nature.
• Recognizing genetic influence aids in developing targeted interventions.
• The role of genetics in society is an ongoing discussion in the field.

Historical context of eugenics and genetics

• Eugenics aimed to control populations without understanding genetics.

• Eugenics as a corrosive ideology to control populations had nothing to do with molecular genetics period.

  — Kian Sadeghi

• The ideology was not based on legitimate genetic science.
• Forced sterilizations were a manifestation of eugenics.

• Forced sterilizations were an incredibly ugly evil manifestation absolutely of an idea that was not limited to forced sterilization.

  — Kian Sadeghi

• Eugenics extended beyond just forced sterilization practices.
• Understanding the historical context helps clarify misconceptions about genetics.
• The separation of eugenics from genetics is crucial for informed discussions.

Ethical considerations in IVF and embryo selection

• The concept of a “best embryo” is fundamentally misguided.

• There’s actually no best embryo right so nucleus is a company and no patient can ever say oh this is the best embryo because there’s no fundamental virtue rooted in biological characteristics.

  — Kian Sadeghi

• Virtue is independent of biological characteristics.
• Parents’ choices are based on personal preferences.

• Virtue is independent of biological characteristics parents can choose based off their preference what they want what is best.

  — Kian Sadeghi

• The subjective nature of parental decisions is emphasized.
• Ethical considerations in IVF involve complex personal values.
• Understanding these considerations is crucial for informed parental choices.

Genetic basis of mental health conditions

• Schizophrenia has a strong genetic basis.

• Schizophrenia is very strongly… there’s a very strong genetic basis of schizophrenia right really correct yeah yeah there is and we know that yes that is a very well established science.

  — Kian Sadeghi

• Understanding genetic factors is crucial for mental health discussions.
• Genetic influence on mental health is supported by scientific consensus.
• This insight highlights the importance of genetics in mental health research.
• Recognizing genetic factors aids in developing effective interventions.
• The role of genetics in mental health is a significant topic in bioethics.
• Understanding genetic influence helps address mental health conditions more effectively.

Parental autonomy in reproductive decisions

• The decision to screen embryos should rest with the parents.

• The decision rests in the parent’s choice a parent can choose not to screen embryos for down syndrome.

  — Kian Sadeghi

• Parental autonomy is a significant topic in bioethics.
• Ethical considerations involve balancing parental rights and societal norms.
• Understanding parental autonomy helps clarify reproductive choices.
• The role of personal values is emphasized in reproductive decisions.
• Parental choices are influenced by complex ethical considerations.
• Recognizing parental autonomy aids in informed discussions on reproductive technology.

Disclosure: This article was edited by Editorial Team. For more information on how we create and review content, see our Editorial Policy.