Only assuming that rationalism is inheritable, which is not at all obvious.
Rationalism may not be heritable, but intelligence surely is.
Let's face it, LessWrong and rationalism in general appeal mostly to people with at least 1 SD above average IQ.
Recently, LWers Will Ryan and Divia Melwani (now Will and Divia Eden) were married, with Eliezer Yudkowsky officiating.
I've been to 40+ weddings in my lifetime, and this was my favorite ceremony yet. Here is the video, and below is the transcript of Eliezer's... what's it called? "Blessing"?