The intensity of light could also have an impact on the intensity of our emotions, a new study suggests.
"Other evidence shows that on sunny days people are more optimistic about the stock market, report higher wellbeing and are more helpful while extended exposure to dark, gloomy days can result in seasonal affective disorder," study researcher Alison Jing Xu, an assistant professor of management at the University of Toronto Scarborough, said in a statement. "Contrary to these results, we found that on sunny days depression-prone people actually become more depressed."
The study included six experiments to examine the link between emotion and ambient brightness. For one experiment, researchers showed that feelings of warmth increased in response to bright light, even when the temperature of the room was kept the same.
In the other experiments, researchers put study participants under different lighting conditions as they rated various things, such as the attractiveness of someone, the spiciness of a sauce, and their feelings toward positive or negative words.
When the study participants were under the brighter lighting, their emotions were more intense: For instance, they wanted the spicier sauce, they thought the person was more attractive, and they thought the positive words were more "positive" and the negative words were more "negative."
Researchers noted that the bright light's ability to make people feel warmer could have something to do with increasing the intensity of their emotions.
"We suggest that these effects arise because light underlies perception of heat, and perception of heat can trigger the hot emotional system," the study said. "Thus, turning down the light, effortless and unassuming as it may seem, can reduce emotionality in everyday decisions, most of which take place under bright light."