The link between violence and hot weather is so intuitive that it’s embedded in our language: Hotheads lose tempers that flare, anger simmers and comes to a boil, and eventually we cool down.
So what does science have to say? Do tempers truly soar with temperature? The answer, appropriately enough for these triple-digit days, is hazy and hotly contested.
To be sure, extensive literature exists on hot weather and violence, stretching from poorly controlled regional studies in the late 19th and early 20th centuries — oh, those hot-blooded southerners! — to more sophisticated modern analyses. This doesn’t just apply to the United States, but countries like England and Wales and New Zealand.
But whether weather is cause or coincidence is difficult to determine.
Perhaps the most detailed studies, led by psychologists Ellen Cohn and James Rotton of Florida State University, involved violent crime over a two-year period in Minneapolis, Minnesota. Cohn and Rotton classified assaults according to time of day, day of week, and month and temperature. They ultimately concluded that violence rose with temperature, but only to a point.