Tuesday 18 February 2020

Why eugenics is wrong

I really didn't think I would need to write a blogpost on this topic, but it seems eugenics is having a resurgence in the UK, so here we go.

The idea of eugenics deceptively simple. Given that some traits are heritable, we should identify those with beneficial heritable traits and encourage them to have more children, while discouraging (or even preventing) those with less desirable traits to breed. This way we will improve the human race.

Those promoting eugenics have decided that high intelligence is a desirable trait, and indeed it does correlate with things like good educational outcomes, earnings and health. It is also heritable. So wouldn't it be great to improve the human race by genetic selection for intelligence?

Much of the debate on this question has focussed on whether it could be done, rather than whether it should be. Many who would blench at enforced sterilisation have warmed to the suggestion that Polygenic Risk Scores can be used to predict educational attainment, and so could be used for embryo selection. However, those promoting this idea have exaggerated the predictive power of polygenic scores (see this preprint by Tim Morris for a recent analysis, and this review of Kevin Mitchell's book Innate for other links). But let us suppose for a moment that in the future we could predict an individual's intelligence from a genetic score: would it be acceptable then to use this information to improve the human race?

The flaw in the argument is exposed when you consider the people who are making it. Typically, they are people who do well on intelligence tests. In effect, they are saying "The world needs more people like us". Looking at those advocating eugenic policies, many of us would beg to differ.

The bad state of the world we live in is not caused by unintelligent people. It is caused by intelligent people who have used their abilities to amass disproportionate wealth, manipulate others or elbow them out of the way. Eugenicists should be especially aware that their advantages are due to luck rather than merit, yet they behave as if they deserve them, and fiercely protect them from "people not like us".

If we really wanted to use our knowledge of genetics to make the world a better place, we would select for the traits of kindness and tolerance. Rather than sterilising the unintelligent, we would minimise breeding by those who are characterised by greed and a sense of superiority over other human beings. But there's the catch: it's only those who think they're superior to others who actually want to implement eugenic policies.


  1. My feeling is that you have a point against a narrowly-defined form of eugenics advocated by some people, but not against eugenics in general. Let me play the devil's advocate.
    Literally, eugenics is the aim to improve the species by improving its genome. So defined, it leaves open:
    - what is considered an improvement.
    - what is considered a legitimate means.
    Regarding improvements: In your post you make a case against higher intelligence being an improvement. It is based on examples of intelligent people doing harm. I am not sure that such examples weigh much against the generally positive correlations between intelligence and desirable outcomes. Regardless of whether one thinks this is sufficient to aim to improve intelligence, in your last paragraph, you provide a perfectly sensible alternative example of what would be a desirable improvement of the human species, and therefore a legitimate motivation for eugenics.
    Regarding means: of course the eugenics movement has in the past used unacceptable means. But killing people considered to carry "inferior genes" is bad because killing is bad (regardless of the motive), not because of the eugenic motive. Sterilising people considered to carry "inferior genes" (or preventing them from procreating) is bad because it violates their basic human rights, not because of the eugenic motive. You mention embryo selection, which is much more acceptable to many people, although not to everybody. Gene editing may offer possibilites that do not even pose the problems of embryo selection.
    So, to the extent that a society eventually reaches an agreement on 1) what constitutes an improvement; and 2) what is a legitimate means, and to the extent that this is actually feasible, what would be a good reason to oppose eugenics?

  2. a. That we won't reach agreement on (1) because people have a strong tendency to think that what is good for the human race is more people like them. I suggest, for instance, that if you had asked Aboriginal people in Tasmania in 1800s what would improve the human species, they might have thought that getting rid of violent colonisers was the solution, whereas the colonisers, of course, thought the opposite. (b) Selecting on one characteristic reduces diversity, and I'd argue that diversity, in general, is good for the human race. I think it's different if you are talking about genetic conditions that are readily identifiable and have dramatic disabling effects where I regard prenatal selection as acceptable. But for normal range variation with polygenetic causes, I don't think we should consider selection, even if the science allowed us to accurately select for individual traits (which it doesn't).

  3. I second deevybee, we should not reduce diversity. This will keep the survivability of our species in the futur maximized. Given all the AI research, it is clear that we still only understand intelligence superficially. Hence, it would be very unintelligent to select on any proxy of intelligence (like IQ) just because we understand that proxy.