I have nothing against splitting infinitives, but "to once they have terms for something take for granted" is pretty extreme. It's likely to overflow the reader's stack. After fixing that, running an iteration of the "omit needless words" algorithm, and doing a bit of rephrasing, here's what I came up with:
There's a related problem: If they have terms for something, humans tend to think things that make syntactic sense actually have semantics behind them.
(Ninja edit: Some more needless words omitted, including a nominalization.)
(Edit 2: Here's a better nominalization link because it gives examples of when to use nominalizations, not just when not to use them.)
[I'd put this in an open thread, but those don’t seem to happen these days, and while this is a quote it isn't a Rationality Quote.]
— Geoffrey K. Pullum, Language Log, “Never fails: semantic over-achievers”, December 1, 2011
This seems like it might lead to something interesting to say about the design of minds and the usefulness of generalization/abstraction, or perhaps just a good sound bite.