It’s four o’ clock in the afternoon. You’re a judge reviewing prisoners up for parole, and you’re about to see the 27th prisoner of the day. No biggie, same routine as before, you listen carefully to what he has to say and make a fair, well-reasoned, fact-based ruling on his fate, right? False, actually, a study published in February 2011 suggests. Researchers from Columbia University looked at parole rulings based on the time of the day that the case was presented, and whether the case took place before or after one of the judge’s food breaks. They found that contrary to consistent, rational ruling, favourable parole rulings started at 65% at the beginning of the day, dropped steadily to zero as more cases were presented, and then jumped back up to 65% again after a food break. This finding is concerning, as it suggests that legal rulings could be swayed by extraneous factors that should have no influence over the decision.
Researchers suggest that the data may be a result of decision fatigue, a phenomenon that is discussed extensively in a New York Times article. Decision fatigue, a deterioration of quality in decision-making, occurs when an individual undergoes a long decision-making session. Studies show that individuals who have to choose between two objects (versus the control of just rating objects one at a time) have a much smaller capability for tasks that require willpower. Individuals are more likely to go with the default option, undergo decision paralysis, and end up making impulse purchases. An exhausted judge hearing the fifth case on a hungry stomach takes the default option – denial of parole – because it preserves the status quo, prevents a potential crime spree, and allows them to keep options open to make a future decision (perhaps when they are less exhausted).
Decision fatigue may be a result of glucose deprivation, a study published in March 2010 strongly suggests. Dogs and humans both exhibit decision fatigue, but a boost of glucose can suppress the negative effects of prior self-control exertion. That may explain why the judges’ food breaks restore the initial parole rate; the intake of glucose restores some element of mental willpower and allows the judge to concentrate on the decision being made instead of his grumbling stomach. In any case, legal rulings should not be based on whether a judge has eaten lunch or not. Perhaps a policy to keep judges nibbling on cookies throughout the day should be instituted, to make sure justice is maintained.
For further reading:
Danziger, S., Levav, J., Avnaim-Pesso, L. Extraneous factors in judicial decisions. PNAS. 2011. 108: 6889-6892.
Miller, H.D., Pattison, K.F., DeWall, C.N., Rayburn-Reeves, R., Zentall, T.R. Self-control without a “self”?: common self-control processes in dogs and humans. Psychol Sci. 2010 Apr. 21(4):534-8.
Vohs, K. D., Baumeister, R. F., Schmeichel, B. J., Twenge, J. M., Nelson, N. M., & Tice, D. M. Making choices impairs subsequent self-control: A limited-resource account of decision making, self-regulation, and active initiative. Journal of Personality and Social Psychology. 2008. 94(5), 883-898.