Further to my previous post, my friend Wolfboy wrote this in the comments:
I also detect a leftover whiff of eugenics in this line of thought – the idea that people who are “bad” represent a taint we need to clear from the gene pool. That seems to be in conflict with modern understanding of how genes work. I may be wrong here, but my understanding was that modern research showed that genes get turned on and off by environmental stimuli. If that’s the case then any genetic predisposition to be an awful person is better handled by stopping it from being triggered (by looking after people better in general) than by trying to breed it out.
Eugenics. That is presumably why the original inquiry was about the prevalence of sterilize-bad-parents views specifically “in the atheist / rationalist community”. Eugenics, the idea of breeding humans for qualities like intelligence or athletic performance, was proposed by Francis Galton as a practical application of the theories of his cousin Charles Darwin. Darwin himself went along with the idea, although never enthusiastically, and with reservations about the social justice implications. The support it enjoyed for the next seventy-odd years came from places all along the left-right political spectrum, but almost entirely from the atheist-materialist side of the religious divide. That is quite possibly the basis for the (otherwise absurd) notion that the Nazis were a scientific and rationalistic bunch.
The Nazis showed the world what it would take to actually implement a eugenics programme, and since then the idea has been anathema among people of conscience. And rightly so, but when a problematic idea or practice becomes unthinkable within a culture, it doesn’t get cut out cleanly. “Not only will we not do this any more,” people decide, “we won’t even go near it.” The classic example (see Steven Pinker’s The Better Angels of Our Nature, and yes, I know I cite that book a lot) is the odd little superstitions that have grown up around knives in European culture, such as not eating with them. Europeans used to use big sharp knives for all sorts of things, notably settling arguments. In Māori culture there are several prohibitions, like “never sit on a table”, which put together underline the point that people are not food. And in modern political discourse, ever since World War II people have been unduly chary of applying genetic science to Homo sapiens.
