Researchers from the University of Toronto Scarborough found that human emotion, whether positive or negative, is felt more intensely under bright light. (Agencies)
Alison Jing Xu, assistant professor of management at UTSC and the Rotman School of Management, along with Aparna Labroo of Northwestern University, conducted a series of studies to examine the unusual paradox of lighting and human emotion.
"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," said Xu.
"Contrary to these results, we found that on sunny days depression-prone people actually become more depressed," she said.
She added that suicide rates peak during late spring and summer when sunshine is abundant.
Xu and Labroo asked participants to rate a wide range of things - the spiciness of chicken-wing sauce, the aggressiveness of a fictional character, how attractive someone was, their feelings about specific words, and the taste of two juices - under different lighting conditions.
They found that under bright lights emotions are felt more intensely.
In the brighter room participants wanted spicier chicken wing sauce, thought the fictional character was more aggressive, found the women more attractive, felt better about positive words and worse about negative words, and drank more of the 'favourable' juice and less of the 'unfavourable' juice.
Xu said the effect bright light has on our emotional system may be the result of it being perceived as heat, and the perception of heat can trigger our emotions.
"Bright light intensifies the initial emotional reaction we have to different kinds of stimulus including products and people," she said.
The majority of everyday decisions are also made under bright light. So turning down the light may help you make more rational decisions or even settle negotiations more easily, researchers said.
Researchers from the University of Toronto Scarborough found that human emotion, whether positive or negative, is felt more intensely under bright light.