How high is the price we would pay for justice?

A sense of justice and injustice is an evolved moral emotion to signal to others that if exchanges are not fair there will be a price to pay. In the Ultimatum Game, in which one person is given a sum of money to divide with another person — with the stipulation that if the offer is accepted both keep the money, but if the offer is rejected no one gets any money — offers less than 30 percent of the sum are typically rejected. That is, we are willing to pay 30 percent to punish an offender. This is called moralistic punishment.

Since personas are powerful in governing decisions and behavior, you can influence whether someone does something and exactly what they do by activating an existing persona. You can activate a persona and connect the persona to specific action. Changing someone’s persona, however, is a little more complicated. Because people like to be consistent in their personas, it’s trickier to get someone to change an existing persona.