“That’s not FAIR!”
This is the line that rings through most houses with at least one kid. We all know when something’s not fair. That car that drove up the shoulder while you waited in traffic (rrrrr)? That’s a cheater, and that’s not fair. The person who cut in line at the grocery store instead of waiting? That’s not fair either.
We get a sense of what is fair or unfair at a pretty young age, and we also understand that we are allowed, and indeed encouraged in some cases, to punish unfair behavior. But we don’t all punish unfair behavior the same way, especially when punishment may be detrimental to us. What is responsible for this difference? What mediates our reactions to what is unfair?
The authors of this study think it might be serotonin, and that it may have as much to do with honesty as it does with a sense of what is fair.