Aside from this being an old theme in SF (I've seen it a lot in works not yet mentioned), it's also the flip side of actual policies & programs in the early 1900s that sterilized people who were considered defective (NOT just in Germany, but also in the good ol' USA) so they wouldn't produce defective children. It's not unbelievable or unpredictable that countries or individuals would try to use technology to "improve" children, if they can. The Chinese program seems to presuppose that a given couple's viable embryos might contain detectable variances in "intelligence" genes. My uneducated guess would be that the variance would likely be small enough that environment & nurture would still play a greater role in the outcome than genetics.
