Math or maths?

A linguist American living in the UK explains the difference. Apparently there’s a folk etymology built up that “math” is plural because “mathematics” ends with an S. But that’s not the only reason something might end with an S — there’s also the collective noun, like “linguistics”.

Interestingly, she’s gone native, saying “maths” despite knowing better, just to avoid the fight. I’m thinking now about other language patterns or other “in-group signals” that people might evince just to avoid a fight despite knowing better.