Moral suasion refers to appealing to a person's sense of morality or ethics in order to influence their behavior.
In one example, the UK Behavioural Insights Team compared reminders to pay taxes. One letter featured a moralistic message ("Paying your taxes is the right thing to do") whereas another empahsized social norms ("9 out of 10 people pay their taxes on time"). The moral suasion message performed worse in this case.
