There is much speculation around when the Ferguson Grand Jury is likely to finally release their (widely expected) no true bill (non-indictment) of Police Officer Darren Wilson over the shooting death of Mike Brown.

A great many people, myself included, have suggested that the authorities responsible for the release of the Grand Jury’s findings would be prudent to wait for colder weather to do so, relying on the conventional wisdom that colder temperatures tend to diminish the frequency and intensity of riots and the other violent behavior (looting, arson) exhibited by the Ferguson protestors.

Legal Insurrection commenter Another Ed, however, has moved us past mere conventional wisdom on this subject by kindly linking to a scientific paper that studies precisely the correlation between riots and temperature.

That paper, “Ambient Temperature and the Occurrence of Collective Violence: A new Analysis,” by JM Carlsmith and CA Anderson of Stanford University, was published in the Journal of Personality and Social Psychology in 1979. It is embedded at the bottom of this post, for those of you who enjoy reading primary research scientific literature.

The Carlsmith paper conducted a re-analysis of earlier research, and found that in fact rioting (or, as they more politely refer to it “collective violence,” as if it were a workshop of some kind) increases “monotonically” with temperature.

The results of their research and analysis?

We conclude that the likelihood of a riot in a given city increases as the maximum ambient daily temperature in that city increases.

They helpfully include a graphical representation of their findings:

#Ferguson Frequency of collective violence as a function of relative temperature

(As an aside, this paper is old enough that the authors sill make use of a null hypothesis to validate their findings. Climate researchers, take note.)

How do these scientific findings apply to the Ferguson Grand Jury?  Well, let us take a look at the average monthly high and low temperatures in St. Louis MO, immediately adjacent to Ferguson.

Ferguson Temps 2

Mike Brown was killed in the month of August, during which the average high temperature is 88F and the average low 70F.  August also “enjoyed” the most violent of the Ferguson protests, as illustrated in the image at the top of this post.

Now, of course, we are in the month of November, with average temperatures (H:56F, L:39F) having dropped roughly 40% from their August figures. This suggests, based on the research of Carlsmith and Anderson that rioting should be much reduced in November relative to August.

Fortuitously for Ferguson, however, they are currently presented with a unique suitable opportunity to take advantage of the riot:temperature correlation in releasing the Grand Jury findings.

Specifically, temperatures for tomorrow, Monday, November 17 are currently being forecast to be well below the historical November average, hovering in the mid-20F’s.

Of course, in considering the effect of temperature on outdoor human activity merely looking at the raw temperature is not enough.  One must also consider the windspeed, in combination with that temperature.  And tomorrow is forecast to be an exceptionally windy day in Ferguson MO, with wind speeds in the range of 20MPH throughout the day.

The website conveniently calculates a “Feels Like” temperature that illustrates this point.  Their calculations show that the “Feels Like” temperature tomorrow will have a high of 16F and a low of (wait for it) 5F.

That’s five degrees Fahrenheit.

I’ve represented the forecast raw temperature, “Feels Like” temperature, and wind speed for November 17 in the graph below.

Ferguson forecast

Based on that graph, I humbly suggest that mid-afternoon might be a particularly well-suited time for release of the news that the Grand Jury has (I expect) declined to indict Officer Darren Wilson.

Anybody care to set up a pool? 🙂

Here’s the Carlsmith and Anderson paper, for your scientific literature reading pleasure:

–-Andrew, @LawSelfDefense

Andrew F. Branca is an MA lawyer and the author of the seminal book “The Law of Self Defense, 2nd Edition,” available at the Law of Self Defense blog (autographed copies available) and (paperback and Kindle). He also holds Law of Self Defense Seminars around the country, and provides free online self-defense law video lectures at the Law of Self Defense Institute and podcasts through iTunes, Stitcher, and elsewhere.


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