It has long been scientifically established that weather changes can affect people's moods. Now, a new study has provided evidence that temperature can influence people's personalities. This study of over 1.6 million people revealed that 22 degrees Celsius is the perfect air temperature to live in. A city with an average annual temperature closer to 22 tends to have a population who are more agreeable, conscientious, emotionally stable, and outgoing. It is the least taxing temperature for the body to regulate its own temperature.
The study was observational and didn't show cause and effect, but the scientists behind it theorized that better weather leads people to leave their home more often. This, in turn, leads to more social interaction, which encourages them to develop a friendlier and socially more acceptable personality. Warmer climates also make people feel more positive in general. They tend to be more agreeable and conscientious.
The findings might help explain why colder and warmer countries tend to produce people with different personalities. Roughly speaking, about 40% of a person's personality is determined by their genes, the other 60% by their environment. It was already well-known that personality traits vary across geographic regions. Scientists also knew that these geographic personality traits are associated with a broad range of consequential outcomes. These outcomes include economic activity, for example, entrepreneurial start-up rates, and also crime rates, health behaviors, and health outcomes.
And it is well established that personality traits differ between countries. The research team speculated the two might be linked. To test this, they gave online personality tests to 5,587 Chinese students and 1.66 million Americans. They then compared the results with the average annual temperature where they grew up. The tests measured personality along five well-studied characteristics. The five were agreeability, conscientiousness, emotional stability, outgoingness, and openness to new experiences. In both groups, the researchers found the closer a town's average annual temperature was to 22 degrees, the more its population exhibited those personality characteristics.
However, the findings were much stronger for the Chinese group than the Americans studied, which suggests that though temperature plays a role, it does not play a dominant role. The effects are fairly weak. It's unlikely to lead to many arguments over the temperature setting of the office air conditioner.