It seems trivial, but last year there were related findings with very real consequences:

"Judges are more lenient after taking a break, study finds. Prisoners are more likely to be granted parole early in the day or after a break such as lunch, according to researchers" (http://www.guardian.co.uk/law/2011/apr/11/judges-lenient-bre...)

Here is the actual paper: http://www.pnas.org/content/108/17/6889