Parwy's Blog: What Embryo Selection Means for Humanity - Chris Williamson with Dr Jonathan Anomaly

Embryo selection technology is still new, leading to some justifiable skepticism from the public and doctors.
It is often confused with gene editing (adding new genes or editing existing ones), which is not what embryo selection involves.
The practice involves revealing more information about the natural genetic variation that already exists within a batch of embryos, allowing prospective parents undergoing IVF to choose which one to implant.
Existing IVF procedures already involve doctors "eyeballing" embryos and using a morphological score to select the one that looks the most normally shaped and healthiest, though the correlation between morphology and viability is not huge.

While 70–75% of Americans support embryo screening for disease, acceptance drops to about 40% for screening for intelligence.
This large gap suggests a taboo around mental traits, particularly intelligence, which is seen as defining what makes us human.
This distinction is thought to stem from post-World War II taboos concerning genetic explanations, which arose partly due to the eugenics programs in Germany that sought to rank humans by their relative worth (often based on mental traits).
In contrast, countries like Singapore show equal support for screening against disease and screening in favor of psychiatric traits, including intelligence.
Mental traits tend to have moral judgments attached more than physical or bodily traits.

The primary concern regarding a "slippery slope" to eugenics relates to government control of reproductive technologies or overwhelming social pressure to use them.
A crucial distinction exists between individuals making informed choices (e.g., to reduce disease risks) and governments coercing people to participate.
The concern that only the rich could afford embryo selection, leading to increased genetic inequality, is balanced against the issue of government overreach.
Subsidizing or mandating insurance coverage to increase access might force people who fundamentally disagree with the technology (e.g., for religious reasons) to pay for it through taxes or premiums. The speaker tends to favor individual choice over equality in this trade-off to avoid coercive government involvement.
Embryo selection is projected to increase existing inequalities slightly (e.g., gaining a few IQ points or inches in height) but is not expected to cause dramatic changes over a generation or two.

Most diseases and traits (like diabetes, schizophrenia, intelligence, height) are polygenic, influenced by hundreds or thousands of genetic variants.
The technology's accessibility has been fundamentally advanced by using data from the standard PGTA (Down syndrome test) combined with whole-genome sequencing of the parents to recreate the entire genome of each embryo.
This innovation democratizes the technology by circumventing the need for doctors or clinics to fully understand polygenic selection, making the information available to parents via these reports.
Polygenic risk scores (PRS) are validated by conducting "within family studies", which predict differences in traits between adult siblings based purely on their DNA.
Companies should be scrutinized on how they validate their PRS and how they perform across different ancestry groups, as scores trained on European data often lose significant accuracy in non-European samples.
The technology can offer substantial risk reduction (e.g., reducing schizophrenia risk by up to half, depending on family history and embryo count). For intelligence, selection across 10 embryos can predict a spread of about 15.5 IQ points, representing half the total expected variation.

A major psychological challenge for parents is the potential for increased guilt or culpability ("buyer's remorse") if the chosen child experiences negative outcomes.
The speaker argues that refusing to use available advantages (like selecting against a severe disease risk) out of guilt over prior children who did not have that option would be morally unsound, similar to refusing a new vaccine.
The ethical landscape is governed by the nonidentity problem (Derek Parfit): since every embryo is genetically distinct, choosing one with better prospects over another does not harm the unchosen individual, as that specific person would not have otherwise existed.
The speaker advocates for drawing hard lines against selecting for traits that are clearly antisocial (like sadism or psychopathy) or selecting for horrific diseases (like Tay-Sachs).
Research suggests that positive pleiotropy is the huge majority of effects; selecting against one negative trait (like severe depression) often results in a lower risk for other related disorders (like bipolar or schizophrenia) due to the underlying "P factor" (general psychiatric risk).
From a personhood standpoint, an embryo is viewed differently from a fetus; the body spontaneously aborts a large proportion of natural pregnancies (estimated at about 40% in the first two weeks) due to genetic abnormalities (aneuploidy) before the woman is even aware she is pregnant.

Understanding the genetic basis of conditions often leads to more compassion, as people realize many outcomes are involuntary, potentially decreasing stigma around diagnoses.
The technology's existence will force society to confront and dismantle the "blank slate" theory of human nature, which is viewed as a catastrophic error, particularly for progressives whose worldviews are tied to it.
Countries lacking post-WWII taboos (Asia, Middle East) or those attempting to boost birth rates (China, Israel) are likely to subsidize or embrace embryo selection rapidly, creating geopolitical pressure on banning countries (like those in Europe) to reverse course.
Selecting for positive traits like IQ is associated with desirable life outcomes, including longer, healthier, and more cooperative lives.