Known as the moral repetition effect, researchers have found that our perceptions of how unethical a particular transgression is tends to be highest when we first learn of it, and decreases with repeated exposure. In other words, repeatedly consuming information about a wrongdoing blunts our perceptions of its unethicality. The moral repetition effect has relevance to both investor client care and investment decision-making.

Researchers have observed the effect across a range of contexts, from minor everyday transgressions to more severe wrongdoings and criminal off...