Some vertical error bars would have been helpful on that plot, but having read the original article (from behind the pay wall) I'm pretty satisfied that they thought about all the obvious problems being discussed in these comments. I am a practicing experimental scientist but with minimal knowledge of statistics, so factor that into whatever I say here.
They point out that a negative ruling ("no" or "almost - come back next time") is much easier to deliver. There is less thought involved, nobody will raise eyebrows and the paperwork is much lighter. So the trend is more about mental energy than grumpiness. They note the significance of the breaks, but do not attempt to disentangle the role of mood improvement / a blood sugar boost / rest.
They explicitly discuss the possibility of hidden variables:
"A key aspect for interpreting the association ... is whether an unobserved factor determines case order in such a way that yields the pattern of results we obtain"
The dip and spike patterns in the rulings are quite pronounced, and similar graphs in the article for parameters such as the gravity of the offense, presence of a rehabilitation plan and the number of previous incarcerations do not show any such trends. This addresses questions about case scheduling by the clerks. Besides which - even if the clerks did organize easier cases for later in the day, this would manifest as one long trend over the entire day, not the spike/decay sequence shown.
So I didn't see any gaping holes, and more importantly it seems quite a plausible conclusion to me. Surely you must have had a similar experience going Christmas shopping - you start out thinking very carefully about getting the perfect gift for every person, but after 3 hours trudging around in a mall you'll just buy any old shit so you can go home. As you get tired you just start taking the easiest options.
They point out that a negative ruling ("no" or "almost - come back next time") is much easier to deliver. There is less thought involved, nobody will raise eyebrows and the paperwork is much lighter. So the trend is more about mental energy than grumpiness. They note the significance of the breaks, but do not attempt to disentangle the role of mood improvement / a blood sugar boost / rest.
They explicitly discuss the possibility of hidden variables: "A key aspect for interpreting the association ... is whether an unobserved factor determines case order in such a way that yields the pattern of results we obtain" The dip and spike patterns in the rulings are quite pronounced, and similar graphs in the article for parameters such as the gravity of the offense, presence of a rehabilitation plan and the number of previous incarcerations do not show any such trends. This addresses questions about case scheduling by the clerks. Besides which - even if the clerks did organize easier cases for later in the day, this would manifest as one long trend over the entire day, not the spike/decay sequence shown.
So I didn't see any gaping holes, and more importantly it seems quite a plausible conclusion to me. Surely you must have had a similar experience going Christmas shopping - you start out thinking very carefully about getting the perfect gift for every person, but after 3 hours trudging around in a mall you'll just buy any old shit so you can go home. As you get tired you just start taking the easiest options.