If you want to change someone's behavior, should you emphasize that the desired behavior conforms to a societal norm, or that their current (undesirable) behavior deviates from a societal norm?
Fortunately, this isn't idle speculation...scientists have already uncovered the answer.
Because people often seek to define themselves based on what makes them unique, they are more attentive to the costs and benefits of associating themselves with behaviors that deviate from, rather than conform to, the perceived norm. This means that attempts to influence other people’s actions should be more successful when the message is framed in terms of diverging from, rather than conforming to, the perceived norm.
In other words, people pay more attention to deviation than conformity.
If you need someone to conform to a norm, emphasize the negatives of not conforming, not the benefits of conforming.
If you need someone to defy a norm, emphasize the postives of not conforming, not the negatives of conforming.
To wit: The majority of my readers do not send me gifts of books and money. But if you do so, you will stand out as unique and earn both my friendship and gratitude.