Not talking about pro forma PC-ness here but true cultural change.
I first noticed this with racism. Note that because I have younger brother over a half generation apart and was raised by people born at the turn of the last century, my perspective has an extra depth IMO.
I was raised in the South and had my first AA classmate in 7th grade (he was one of 3 in jr high school). I remember when bathrooms, restaurants, water fountains, movie theatres were segregated. When still in junior high, Sammy Davis Jr was a scandal because he was married to a white woman. In high school and even in college, I was called an N-lover. My brothers' generation was much less racist as a group, and by the 80s, the children simply weren't (exceptions still existed among poor whites and the less educated). By the 3rd generation, with the exceptions noted, anti-racism has been institutionalized. I still notice inter-racial couples IRL and in the media; B simply does not. I will say that among AAs, racism about White people is still rife...with the rider that AA people cannot be racists, only White folks can.
During this time (until they died), I noticed a large change among my grandparents' and parents' generations, but it was more of an acceptance rather than being institutionalized.
I think the same thing is true about sexism. I notice B's (and his friends') distaste over any form of sexism. B will frequently comment when he sees any, even when it is oblique.