Well, it used to be called “assimilation.” But if I had to guess when it started being called “cultural appropriation” I’d say it started in the age of Jazz, when white people started copying cool black phrases and terms, such as “man,” and “cat,” and “cool,” back in the 20s and we never stopped because we wanna be as cool as black people! But we are jive turkey honkys and we can never be as cool as black people and most of us look silly when we try.