Let’s start with what’s not true. China is not “engineering” babies. Even if it were, Chinese scientists wouldn’t know how to genetically engineer a genius. And even if they did know how to genetically engineer a genius, the fact is that you can’t ensure genius, because genius depends on environment as well as genes.

What is true, though, is fascinating, exciting, and troubling. Scientists are already developing the capacity to screen human embryos for a wide variety of genetic disorders, such as cystic fibrosis and sickle-cell anemia. At Reprogenetics, a private laboratory in New Jersey, couples who carry a genetic disease can have their embryos checked for the mutation before implanting them in the woman’s uterus. The process is referred to as preimplantation genetic diagnosis, and the technology is advancing rapidly. Santiago Munné, the lab’s director, told me that within a year he expects to be able to offer embryo analyses that screen for more than 100 diseases at once, for a few thousand dollars.

Women are already using preimplantation analysis to select the gender of their embryos. And in the United States, they’re overwhelmingly choosing to have daughters.

The next leap will be to whole-genome sequencing of embryos. That opens the door to screening not just for sex or single-gene disorders but for more complex disorders like autism—or even, conceivably, qualities like physical attractiveness or intelligence.