As The World Gets Hotter, We Need To Figure Out Why Heat Makes Us Violent

Violence spikes in hotter months and is higher in hotter climates. There’s a new theory about why.

As The World Gets Hotter, We Need To Figure Out Why Heat Makes Us Violent
[Photo: Flickr user liz west]

When temperatures climb, tempers fray. All those people out on the street rub up against each other and things explode. If you live in a big city, you know this (as do the police). But why does it happen? An interesting new explanation suggests that the heat makes people lose the ability to think ahead and minimizes their self-control.


The new theory is called Climate Aggression and Self-Control in Humans (CLASH), and comes from Cambridge University in the U.K. Current guesses about the escalation of aggression in hot weather take two approaches. To oversimplify: One is that hot weather makes us grouchy, because we’re uncomfortable. The other is that people who live in warmer places spend more time outside, and therefore are offered more opportunity for other people to annoy them and then to do something drastic about it.

Chao pavit via Shutterstock

CLASH is slightly different and is built on the fact that, in general, violence is higher in places closer to the equator. And while equatorial countries are hotter, they have another distinctive climate trait: The weather doesn’t change much. It’s always hot, day after day.

And it’s this relentless lack of change that causes the problem, say the writers of the paper. Because every day is the same as the last, people don’t need to plan as well for the future (you don’t need to make sure you have wood for the winter, say) and this can lead to a present-ism that makes violent behavior more likely.

The CLASH model further outlines that fast-life strategy, short-term orientation, and lack of self-control are important determinants of aggression and violence.

The authors insist their meta-study isn’t just a reverse engineering of why Scandinavians are better than people in the global south. The authors focused north-south differences in individual countries and found the same thing: Violence is noticeably higher near the equator than farther away. And perhaps you can sympathize. Remember this during the worst days of summer and see how you feel about your fellow humans.

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Previously found writing at, Cult of Mac and Straight No filter.