That makes the answer obvious, doesn't it.

All he needs to do is guess that dath ilan prefers not to lie, and that natural selection in dath ilan worked the way it obviously should.

"Dath ilan has people who want to inflict pain sexually.  It doesn't have the people who want to be sexily hurt.  I'm not sure why they exist in Golarion, but whatever that reason was, it didn't operate in dath ilan.  That's why I was never supposed to notice."

That makes the answer obvious, doesn't it.

All he needs to do is guess, first, that dath ilan prefers not to lie, and second, that natural selection in dath ilan worked the way it obviously-intuitively should.  By default, organisms don't like pain, and pain is what they don't like.

"Dath ilan has people who want to inflict pain sexually.  It doesn't have the people who want to be sexily hurt.  I'm not sure why they exist in Golarion, but whatever that reason was, it didn't operate in dath ilan.  That's why I was never supposed to notice."

That makes the answer obvious, doesn't it.

All he needs to do is guess, first, that Civilization prefers not to lie, and second, that natural selection in dath ilan worked the way it obviously-intuitively should.  By default, organisms don't like pain, and pain is what they don't like.

"Dath ilan has people who want to inflict pain sexually.  It doesn't have the people who want to be sexily hurt.  I'm not sure why they exist in Golarion, but whatever that reason was, it didn't operate in dath ilan.  That's why I was never supposed to notice."