Why does the hot weather make people so bad tempered?

We spend the whole of winter moaning about the cold and wishing it was hot. Yet when the sun finally comes out we become utterly grumpy and bad tempered. Why? Is it because we are simply British, or is there more going on?

Well according to Frank McAndrew, a professor of Psychology at Illinois based Knox College, there is actually science behind this phenomenon.

Writing in Psychology Today, he cited numerous studies observing these trends.

He said some studies in which people believe they are receiving electric shocks and act aggressively show correlation between increased aggression and higher temperatures.

And if that wasn’t conclusive enough, he also said other studies show that violent crime increases when temperatures are hotter, and nonviolent crime does not.

“Some studies even suggest that baseball pitchers throw more aggressively in hot weather, as there is an increase in the number of batters hit by pitches on hot days,” he added in the article, which was published in 2019.

“This does not appear to occur because pitchers are fatigued or wilder, as there are not more walks or wild pitches in hot weather—it looks as if the pitchers are simply hitting more batters intentionally.”

It comes in the midst of a heatwave in England. On Sunday, the hottest day of the year was recorded as parts of the country reached 34C and temperatures are expected to remain high for the rest of the week.

Meanwhile, according to Christian Jarrett, a cognitive neuroscientist, “heat makes us feel physically uncomfortable, we’re more inclined to aggressive thoughts and to interpret things in a negative way”.

Writing in Science Focus, he added: “There are tentative biological explanations, too, with recent Scandinavian research identifying a link between higher temperatures and raised serotonin levels – a brain chemical that’s related to impulsivity, among other things.”

Meanwhile, McAndrew also said that the hot makes people less attracted to others, less likely to do nice things for others and more likely to honk their horns while driving.

And if that wasn’t bad enough, the heat can have a negative impact on health, he said.

“The effects of prolonged heat stress can range from exhaustion and headaches to delirium, heart attacks, and death. In other words, heat does not only make us angry—it can also make us sick.”

Winter doesn’t sound so bad now after all.