This article discusses inventions that we don't realize are very recent. So the time they were invented may be an invertible fact to many people. The article is on Cracked.com so the claims should be verified carefully (although sometimes I feel that they do more fact checking than much of the official media.) Highlights include the doorknob (invented in 1878. I would have guessed last thousand years, but certainly not that recently). One on the list, timzonzes struck me as very obviously recent, but that may be because I've read a bit about the history of railroads. I also don't think the example of "nationalism" is quite correct, or at least, they are drastically oversimplifying in that entry. But the overall thrust might do what you want.
I'm writing the section of the rationality book dealing with hindsight bias, and I'd like to write my own, less racially charged and less America-specific, version of the Hindsight Devalues Science example - in the original, facts like "Better educated soldiers suffered more adjustment problems than less educated soldiers. (Intellectuals were less prepared for battle stresses than street-smart people.)" which is actually an inverted version of the truth, that still sounds plausible enough that people will try to explain it even though it's wrong.
I'm looking for facts that are experimentally verified and invertible, i.e., I can give five examples that are the opposite of the usual results without people catching on.
Divia (today's writing assistant) has suggested facts about marriage and facts about happiness as possible sources of examples, but neither of us can think of a good set of facts offhand and Googling didn't help me much. Five related facts would be nice, but failing that I'll just take five facts. My own brain just seems to be very bad at answering this kind of query for some reason; I literally can't think of five things I know.
(Note also that I have a general policy of keeping anything related to religion out of the rationality book - that there be no mention of it whatsoever.)