Researchers have long struggled to explain why some violent crime rates are higher near the equator than other parts of the world. Now, a team of researchers have developed a model that could help explain why.
This new model goes beyond the simple fact that hotter temperatures seem to be linked to more aggressive behavior.
The researchers believe that hot climates and less variation in seasonal temperatures leads to a faster life strategy, less focus on the future, and less self-control – all of which contribute to more aggression and violence.
“Less variation in temperature, combined with heat, brings some measure of consistency to daily life”, Rinderu said.
That means there is less need to plan for large swings between warm and cold weather. The result is a faster life strategy that isn’t as concerned about the future and leads to less need for self-control.
“Strong seasonal variation in temperature affects culture in powerful ways. Planning in agriculture, hoarding, or simply preparing for cold winters shapes the culture in many ways, often with people not even noticing it. But it does shape how much a culture values time and self-control,” Van Lange said.
“If there is less variation, you’re freer to do what you want now, because you’re not preparing foods or chopping firewood or making winter clothes to get you through the winter. You also may be more concerned with the immediate stress that comes along with parasites and other risks of hot climates, such as venomous animals.”
People living in these climates are oriented to the present rather than the future and have a fast life strategy – they do things now.
“We see evidence of a faster life strategy in hotter climates with less temperature variation – they are less strict about time, they have less use of birth control, they have children earlier and more often,” Bushman said.
With a faster life strategy and an orientation toward the present, people have to practice less self-control, he said. That can lead people to react more quickly with aggression and sometimes violence.
The theory is not deterministic and isn’t meant to suggest that people in hotter, consistent climates can’t help themselves when it comes to violence and aggression.
“How people approach life is a part of culture and culture is strongly affected by climate,” Van Lange said. “Climate doesn’t make a person, but it is one part of what influences each of us. We believe it shapes the culture in important ways,” he said.