Extraneous factors in judicial decisions.
Level 3 - non-randomized controlled study
Observational study analyzing sequential outcomes over time
PubMed 21482790 · doi:10.1073/pnas.1018033108
What was done
Sequential parole decisions made by experienced judges were tracked across daily deliberations. Researchers recorded judges' two daily food breaks, dividing each day into three distinct decision sessions to assess the impact of session progression and breaks on ruling outcomes.
What was found
The percentage of favorable parole rulings declined gradually from approximately 65% to nearly zero within each decision session. Following a food break, the rate of favorable rulings returned abruptly to approximately 65%.
Why it matters
These findings suggest that judicial outcomes may be swayed by extraneous, non-legal variables such as decision order and scheduled breaks, challenging the legal formalist assumption that rulings depend strictly on facts and law.
Limits
The abstract does not state the number of judges, cases, or court sessions observed, nor does it describe the specific legal jurisdiction. Because this is an observational design, the abstract does not report whether cases were randomly ordered or if confounders—such as case complexity, legal representation, or prisoner status—systematically differed across session positions. Direct physiological measures of hunger or fatigue were not reported.
Cited by
- supports Research on judicial rulings demonstrates that parole decisions systematically differ depending on whether cases are heard before versus after lunch breaks.