I wrote a scene in my fantasy WIP where a character was beginning to agree with the antagonist. Later on in the work, a supporting character asked him if the MC had Stockholm Syndrome. Then my brain, with a very good catch, thought of something really interesting that made me stop in my tracks.
In a fictional work, specifically works that do not take place in the world as we know it, is it even possible to use a phrase like "Stockholm Syndrome" when Stockholm never existed and the Norrmalmstorg robbery never happened? I tried thinking of other words or phrases to describe this syndrome, but none of them are as concise. I'm stuck on this one, and my research has proved unfruitful. What's your take? Yay or nay?
VERY interesting question.
If we take the lead from historicals, then the answer is no. The always Fabulous Gary Corby's great crime novels set in ancient Athens can't refer to things that the ancient Athenians didn't know or have. Let me tell you, that's a really interesting list. You can be if we miss something, his discerning readers let us know pronto.
However, if the world is fictional, who's to know what happened or when? I think Stockholm Syndrome which is so closely identified with a modern event, and entered the lexicon relatively recently is more problematic than say January, which indicates have a concept of linear time and cyclical seasons.
Not being able to use Stockholm Syndrome, or 23Skidoo, or QueryShark, or selfie, is a high price to pay for writing fantasy. On the other hand...dragons!
I don't think there's a right or wrong answer here, but if you use it, you'll hear from readers who do have strong opinions one way or the other.