Outcomes matter more than intention when choosing to punish or reward individuals who’ve caused accidents, according to new research from Harvard University.

Published in PLoS One, the study was led by Fiery Cushman, a postdoctoral researcher in the Department of Psychology in Harvard’s Faculty of Arts and Sciences, along with Anna Dreber of the Program for Evolutionary Dynamics at Harvard and the Stockholm School of Economics.

“Punishing those who’ve caused accidents seems to be something that people do routinely,” says Cushman. “I think that it’s useful for ordinary people and policymakers to notice this and to ask whether it might be fairer to focus on intent.”

He says that while we may not often consider — and might even disavow — our tendency to punish those who’ve inadvertently caused damage, it’s possible that punishing accidents has an adaptive value by teaching others when to “watch out.”

The findings have implications for legal and policy decisions, since our laws often punish accidental outcomes, regardless of intent. For example, Cushman says, a distracted driver talking on a cell phone who causes property damage generally receives a much more lenient sentence than one who crashes into a person — even though the nature of the damage is pure chance.

Cushman’s study involved a two-player economic game where one participant had some control over how to allocate $10. By choosing which of three dice to roll, this player could try to keep all the money, a tactic referred to as “stingy” in this study; give the money to a second player, a behavior called “generous”; or split the money evenly, called “fair.”

Each of the three dice was weighted with a high probability for either a stingy, generous, or fair outcome. By selecting the stingy die, the participant demonstrates intent to keep all the money, but an “accidental” generous outcome remains possible. Similarly, an unexpected stingy outcome is possible even when using the generous die.


“If you chose the stingy die and were trying to keep the money for yourself, but it happened to all go to me, I tend to reward that behavior,” says Cushman. “And if you chose the generous die that was supposed to give all of the money to me, but then accidentally it came up that the money went to you, I might actually tend to punish that behavior, even though there was a generous intention.”


Cushman and Dreber’s co-authors are Ying Wang and Jay Costa, both of whom contributed to the research as Harvard undergraduates.

The research was funded by the Mind/Brain/Behavior Initiative at Harvard University.