[pron]

It's interesting that you bring up disgust, because that exact reaction is at the core of the seminal work by the sociologist Norbert Elias, The Civilizing Process[1].

He traces the evolution of manners through etiquette books (a remarkably enduring genre going back many centuries), and shows how things that evoke a strong digust response in us today were actually slow-evolving social norms that have been internalized and turned into habitus (or a super-ego), and he even mentions urine, which for a long while hadn't evoked the same reaction as today. For example, some centuries ago in Europe, urinating under the staircase indoors was actually quite acceptable, and blowing your nose into the tablecloth was considered good manners.

This, of course, doesn't mean that the capacity for disgust isn't evolutionary, but that its particular triggers are social, even though we perceive them to be natural.

[1]: https://en.wikipedia.org/wiki/The_Civilizing_Process