In a very interesting and disturbing article Shai Danziger and coworkers have examined the rejection rates in parole decisions in Israel. Israeli judges decide about paroling in 6 minutes on average and take two food breaks while working: one snack at 10 AM and lunch at about 1.30 PM. Their working time is therefore divided in three periods. Danziger and colleagues show that the probability of getting a positive parole decision are much higher than usual if the case is examined by the judge when her mind is ‘fresh’, i.e. immediately after the break at the beginning of a period. Cases that are legally similar are often decided in a dissimilar way, since the moment of the day in which they are presented in front of the judge exerts a major influence. As the judge herself decides when to take the break and she is ignorant of the details of the upcoming cases, the effect cannot be driven by some partiality of the judge relative to the characteristics of the prisoners. The authors interpret the results in terms of depletion of mental resources: taking complex decisions several times leads to adherence to the status quo, that in this case is rejection. Nonetheless the authors are admittedly unable to rule out competing explanations, such as those based on mood (maybe the break enhances the judge’s mood). Furthermore, no measure of judges’ mental resources was carried out and there is hence no way to track their variation over time. In spite of these admitted shortcomings, the results do indeed show that judicial decisions are not taken in the way legal formalism describes. This ‘food bias’, together with the adoption of unconscious heuristics (see e.g. Gigerenzer G. 2007. Moral Intuition = Fast and Frugal Heuristics, in Sinnott-Armstrong W (ed). Moral Psychology vol. 2 Cambridge (Mass): MIT Press, p.12), shows that judges often rule without sufficient reflection, in a way that is not compatible with the idealized picture of the law legal formalism envisions. It would be interesting to investigate the neural correlate of this bias, but it would be difficult to convince judges to rule parole cases inside a noisy MRI scanner.
Shai Danziger, Jonathan Levav, and Liora Avnaim-Pesso. 2011. Extraneous factors in judicial decisions. PNAS early edition. doi: 10.1073/pnas.1018033108
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