Reportedly, a lot of people who choose to study psychology are motivated originally to figure out what's going on in their own heads (which they have a sense is not quite normal) [1]. I wonder if there's a similar dynamic with "honesty / ethics": people who lack a native impulse to be honest / ethical and are curious about people who do.
[1] See e.g., https://news.ycombinator.com/item?id=39703638 from yesterday