Jonathan Levav of Columbia Business School in New York and his colleagues analyzed 1,112 parole hearings for inmates of four Israeli prisons, made by eight judges over a ten-month period.The article, as all scientific articles do, includes the appropriate dose of skepticism. And it's obviously wrong to presume that the judges are too harsh when they're hungry; after all, they might be too lenient when full.
Judges' days were divided into three sessions broken by two meal breaks -- a morning snack and lunch. Judges decided when to break, but had no control over the ordering of cases, which was determined by when a prisoner's attorney arrived.
At the beginning of a session, a prisoner had a 65% chance of being paroled, the authors found. This declined to almost zero by the end of a session, and leaped back to 65% after a break.
The severity of the crime, the time served in prison, any previous incarcerations, and the availability of rehabilitation programs were not enough to explain the effect on the probability of parole, and the nationality or sex of a prisoner made no difference. The findings are published this week in the Proceedings of the National Academy of Sciences.
Still, it makes one wonder what would happen if courts instituted mandatory snack breaks.