Does heat make people aggressive? | STERN.de

The train stops in Lübeck – and everyone wants to get on the next crowded train with their beach bags to go to the sea from Hamburg on one of the last days of late summer with temperatures around 30 degrees Celsius. But an argument between two women interrupts the anticipation. “Don’t push me,” calls a lady with glasses in a patterned shirt to a young woman in bell-bottoms and 90s sunglasses who hurriedly scurries past.

And before she knows it, the young woman gets a loud slap in the face. The rest of the passengers are dismayed. A man from DB security checks that everything is going well and the women part, cursing, without further outbreaks of violence. And on the way to the Bay of Lübeck I’m left with the question of whether the heat isn’t just literally going to people’s heads.

It quickly becomes clear that the phenomenon has a name: “Long Hot Summer Effect”. It describes the fact that people behave more aggressively and are more easily irritable at high temperatures. The scientists Paul A. Bell and Robert A. Baron investigated the phenomenon of heat and aggression back in the 1970s. They divided 64 male students into two groups. One group was allowed to criticize the other. The other was allowed to punish her with electric shocks. And: the hotter it was in the test room, the more often the students gave their critics electric shocks.

Heat and aggression

The influence of heat on behavior is wide-ranging: temperatures and penalties in professional football (National Football League in the USA) showed that the hotter it was, the more players committed rule violations. The home team in particular tended to behave aggressively. The researchers therefore assume that, in addition to the heat, the fans present could also play a role. The heat also seems to have an effect on drivers in road traffic: Research staff “missed” the green traffic light. On hot days, the displeasure of waiting drivers was particularly great: it ended in particularly loud honking. Those who didn’t have air conditioning in their car honked the horn most often.

In addition to these rather harmless consequences, heat also seems to have more drastic effects: over a period of 45 years, the USA found that violent attacks increase in warm years and seasons. On the other hand, researchers came to the conclusion that people are less helpful in high temperatures. The US scientist Craig Anderson showed more than 20 years ago that more violent and sexual crimes are committed during heat waves. One from 2021 even showed that on very hot days, violence among inmates in prisons increases by 18 percent.

However, due to their design, the results of such experiments and studies can only ever be viewed as an indication of a connection. So you can’t prove that the increased aggressiveness in heat is actually due to this. The researchers cannot rule out that other factors, such as more people spending time outdoors or more alcohol consumption, also play a role.

Comfortable temperature for Central Europeans: 22 to 25 degrees Celsius

One thing is certain: heat has a direct effect on our bodies. In addition to the obvious fact that the body increases sweat production in hot weather so that the body temperature does not get too high, the blood vessels also dilate. This causes blood pressure to drop. The heart responds by increasing its pumping capacity. Heat can therefore act as a stressor on us.

For Central Europeans, the comfortable temperature is around 22 to 25 degrees Celsius, Professor Hanns-Christian Gunga told . He set up the Center for Space Medicine and Extreme Environments at the Berlin Charité. If the thermometer climbs to 30 degrees or more, this is too much for Central Europeans. A possible explanation for the aggressive behavior in heat is the hormone vasopressin, which regulates water balance and is increasingly released by the body at high temperatures. Because: The body tries to store as much fluid as possible and therefore releases more hormones. But this not only has an impact on the water balance, the hormone also increases our willingness to be aggressive.

Heat can make us feel uncomfortable

There could also be a very banal explanation for why the warm weather drives us so crazy: we quickly become irritated when we feel unwell. . Among other things: increased sweating, poor sleep, fatigue and

He suspects that when the weather is stressful, people tend to misunderstand ambiguous situations and that this can lead to more misunderstandings and conflicts.

High temperatures can have a negative impact on mental health

In addition to aggression, heat can also lead to more… “During a heat wave, there is a significant increase in stress, anxiety and depression, especially among older and weaker people, but also among younger people who lack fitness. The prospect of not being able to escape this heat leads to psychological distress Problems that should not be underestimated,” explains Hans-Peter Hutter, environmental medicine specialist from MedUni Vienna. This could lead to, among other things, panic attacks.

from the USA and Mexico even come to the conclusion that the risk of suicide is increased on hot days.