Professor Bainbridge...on law, politics, religion, culture & food

From the “Why is That?” File

John Scalzi:

… being as I am in science fiction/nerd circles, I have a fair number of friends who are openly polyamorous, and some who are in functionally polygamous relationships, which is to say, there’s more than two of them who live and function as a household.

It’s certainly the case that polyamory crops up in a lot of science fiction. I’m also under the vague impression that a lot of polyamorous folks are SF and fantasy fans. But is there a correlation? And, if so, why?