I don’t know why Tielbeek says that, unless he’s confusing SNP heritability with PGS: a SNP heritability estimate is unconnected to sample size. Increasing n will reduce the standard error but assuming you don’t have a pathological case like GCTA computations diverging to a boundary of 0, it should not on average either increase or decrease the estimate… Better imputation and/or sequencing more will definitely yield a new, different, larger SNP heritability, but I am really doubtful that it will reach the family-based estimates: using pedigrees in GREML-KIN doesn’t reach the family-based Neuroticism estimate, for example, even though it gets IQ close to the IQ lower bound.
Thanks, all of that makes sense, agree. I also wondered why SNP heritability estimates should increase with sample size.
To summarize, my sense is the following: Polygenic scores for personality traits will likely increase in the medium future, but are very unlikely to ever predict more than, say, ~25% of variance (and for agreeableness maybe never more than ~15% of variance). Still, there is a non-trivial probability (>15%) that we will be able to predict at least 10% of variance in agreeableness based on DNA alone within 20 years, and more than >50% probability that we can predict at least 5% of variance in agreeableness within 20 years from DNA alone.
Or do you think these predictions are still too optimistic?
But couldn’t one still make use of rare variants, especially in genome synthesis? Maybe also in other settings?
The value of the possible selection for the foreseeable future will be very small, and is already exceeded by selection on many other traits, which will continue to progress more rapidly, increasing the delta, and making selection on personality traits an ever harder sell to parents since it will largely come at the expense of larger gains on other traits.
I agree that selecting for IQ will be much easier and more valuable than selecting for personality traits. It could easily be the case that most parents will never select for any personality traits.
However, especially if we consider IES or genome synthesis, even small reductions in dark personality traits—such as extreme sadism—could be very valuable from a long-termist perspective.
For example, assume it’s 2050, IES is feasible and we can predict 5% of the variance in dark traits like psychopathy and sadism based on DNA alone. There are two IES projects: IES project A only selects for IQ (and other obvious traits relating to e.g. health), IES project B selects for IQ and against dark traits, otherwise the two projects are identical. Both projects use 1-in-10 selection, for 10 in vitro generations.
According to my understanding, the resulting average psychopathy and sadism scores of the humans created by project B could be about one SD* lower compared to project A. Granted, the IQ scores would also be lower, but probably by no more than 2 standard deviations (? I don’t know how to calculate this at all, could also be more).
It depends on various normative and empirical views whether this is worth it, but it very well might be: 180+IQ humans with extreme psychopathy or sadism scores might substantially increase all sorts of existential risks, and project A would create almost 17 times** as many such humans compared to project B, all else being equal.
The case for trying to reduce dark traits in humans created via genome synthesis seems even stronger.
One could draw an analogy with AI alignment efforts: Project A has a 2% chance of creating an unaligned AI (2% being the prevalence of humans with psychopathy scores 2 SDs above the norm). Project B has only a 0.1% chance of creating an unaligned AI. Project B is often preferable even if it’s more expensive and/or its AI is less powerful.
*See the calculation in my above comment: A PGS explaining 4% of variance in a trait can reduce this trait by 0.2 standard deviations in one generation. This might enable 1 SD (?) in 10 in vitro generations; though I don’t know, maybe one would run out of additive variance long before?
**pnorm(12, mean=10, sd=1, lower.tail=FALSE) / pnorm(12, mean=9, sd=1, lower.tail=FALSE) = 16.85. This defines extreme psychopathy and/or sadism as being 2 SDs or more above the norm, assumes that these traits are normally distributed, and that project B indeed has average scores of 1SD less than project A. (It also assumes IQ means for the two projects are identical, which is not realistic.)
Thanks, all of that makes sense, agree. I also wondered why SNP heritability estimates should increase with sample size.
To summarize, my sense is the following: Polygenic scores for personality traits will likely increase in the medium future, but are very unlikely to ever predict more than, say, ~25% of variance (and for agreeableness maybe never more than ~15% of variance). Still, there is a non-trivial probability (>15%) that we will be able to predict at least 10% of variance in agreeableness based on DNA alone within 20 years, and more than >50% probability that we can predict at least 5% of variance in agreeableness within 20 years from DNA alone.
Or do you think these predictions are still too optimistic?
Interesting, thanks.
But couldn’t one still make use of rare variants, especially in genome synthesis? Maybe also in other settings?
I agree that selecting for IQ will be much easier and more valuable than selecting for personality traits. It could easily be the case that most parents will never select for any personality traits.
However, especially if we consider IES or genome synthesis, even small reductions in dark personality traits—such as extreme sadism—could be very valuable from a long-termist perspective.
For example, assume it’s 2050, IES is feasible and we can predict 5% of the variance in dark traits like psychopathy and sadism based on DNA alone. There are two IES projects: IES project A only selects for IQ (and other obvious traits relating to e.g. health), IES project B selects for IQ and against dark traits, otherwise the two projects are identical. Both projects use 1-in-10 selection, for 10 in vitro generations.
According to my understanding, the resulting average psychopathy and sadism scores of the humans created by project B could be about one SD* lower compared to project A. Granted, the IQ scores would also be lower, but probably by no more than 2 standard deviations (? I don’t know how to calculate this at all, could also be more).
It depends on various normative and empirical views whether this is worth it, but it very well might be: 180+IQ humans with extreme psychopathy or sadism scores might substantially increase all sorts of existential risks, and project A would create almost 17 times** as many such humans compared to project B, all else being equal.
The case for trying to reduce dark traits in humans created via genome synthesis seems even stronger.
One could draw an analogy with AI alignment efforts: Project A has a 2% chance of creating an unaligned AI (2% being the prevalence of humans with psychopathy scores 2 SDs above the norm). Project B has only a 0.1% chance of creating an unaligned AI. Project B is often preferable even if it’s more expensive and/or its AI is less powerful.
*See the calculation in my above comment: A PGS explaining 4% of variance in a trait can reduce this trait by 0.2 standard deviations in one generation. This might enable 1 SD (?) in 10 in vitro generations; though I don’t know, maybe one would run out of additive variance long before?
**pnorm(12, mean=10, sd=1, lower.tail=FALSE) / pnorm(12, mean=9, sd=1, lower.tail=FALSE) = 16.85. This defines extreme psychopathy and/or sadism as being 2 SDs or more above the norm, assumes that these traits are normally distributed, and that project B indeed has average scores of 1SD less than project A. (It also assumes IQ means for the two projects are identical, which is not realistic.)