This has been out of the box already for a while. You can literally have your embryo commercially screened for intelligence, height, and other complex traits today
Has it been out of the box long enough to validate that the adult versions of the embryos exhibit the traits that they're supposed to? Is it a noticeable intelligence boost? For example, a standard deviation higher IQ as measured by Raven's Progressive Matrices, compared to siblings from un-screened embryos? I read enough about biotech and biohacking that I feel like I would have already come across reports if this really works, but maybe it's very recent.
I read Gwern's "Embryo Selection for Intelligence" a few years ago:
Near future possibilities seemed pretty limited based on that review, unless the reasoning was incorrect:
As median embryo count in IVF hovers around 5, the total gain from selection is small, and much of the gain is wasted by losses in the IVF process (the best embryo doesn’t survive storage, the second-best fails to implant, and so on). One of the key problems is that polygenic scores are the sum of many individual small genes’ effects and form a normal distribution, which is tightly clustered around a mean. A polygenic score is attempting to predict the net effect of thousands of genes which almost all cancel out, so even accurate identification of many relevant genes still yields an apparently unimpressive predictive power. The fact that traits are normally distributed also creates difficulties for selection: the further into the tail one wants to go, the larger the sample required to reach the next step—to put it another way, if you have 10 samples, it’s easy (a 1 in 10 probability) that your next random sample will be the largest sample yet, but if you have 100 samples, now the probability of an improvement is the much harder 1 in 100, and if you have 1000, it’s only 1 in 1000; and worse, if you luck out and there’s an improvement, the improvement is ever tinier. After taking into account existing PGSes, previously reported IVF process losses, costs, and so on, the implication that it is moderately profitable and can increase traits perhaps 0.1SD, rising somewhat over the next decade as PGSes continue to improve, but never exceeding, say, 0.5SD.
Just saw your quoted text, and I do think the reasoning is incorrect.
What is gets right is that there are some serious practical limitations. The most important are around the availability of embryos, financial costs, and diminishing returns.
What it gets wrong is modeling the implementation as an optimization tool opposed to a screening tool.
If you have a pool 10 embryos, with a trait on a normal distribution (eg IQ), you can screen the bottom half out. By doing so, the average IQ goes from 100 (normal mean) to 110, mean for embryos over 100.
People want genetic children, but if for example, a wife is infertile, eggs can be purchased for ~$2.5k.[1]
Using today's technology, you could buy 100 eggs, screen the top 10% (>120), and the average embryo in the pool would be now be the 95th percentile for IQ (eg 125, +1.66 Standard deviations above the mean)
The next technology needed to knock this wide open would the the cloning or duplication of human eggs from a single source. IVT egg extraction yields only 5-10 eggs per cycle. If this could be multiplied in-vitro, money would be the only constraint.
For polygenic traits no, it hasnt been out of the box long enough for the embryos to mature.
However, we have been screening for single gene mutations that impact IQ since the the 1960s and they are well validated. For example, the impact on IQ of Trisomy 21 (downs syndrome) has a well validated impact of about 30 IQ points. 16p11.2 Gene abnormality has a well studied impact of 16-25 IQ points depending on the abnormality.
If you had a dumb as rocks polygenic test that screened just these factors, you would see a noticeable difference compared to a control.
