If you ever feel like your emotions are getting the best of you, you may want to try dimming the lights.

According to researchers at the University of Toronto Scarborough, bright light can make us more emotional — for better or for worse — making us experience both positive and negative feelings more intensely.

The findings seem to contradict commonly held notions that people feel happier and more optimistic on bright, sunny days and gloomier on dark, cloudy days.

In fact, the idea for the study was spurred by findings that suicide rates peak in the late spring and summer, when sunshine is most abundant.

“I was very surprised by this,” study author Alison Jing Xu told CBC News. Xu is an assistant professor of management at UTSC and the Rotman School of Management.

“Normally I would say if brighter days generally increase people’s affect, then suicide rates should peak in winter — but actually it does not,” she said.

Xu, along with the study’s co-author Aparna Labroo of Northwestern University in the U.S., conducted six experiments to explore the relationship between light and emotion. Their paper is published in the Journal of Consumer Psychology.

Participants in each case were divided into two groups: Some were placed in a brightly lit room where fluorescent ceiling lights were turned on, while others were placed in a dimly lit room where the only light came from computer monitors.

Stronger emotions, spicier foods

In one experiment, participants were given scripts for a television commercial featuring a fictitious character named Alex, who acted in ways that could be perceived as aggressive as he was running late for work. The participants were then asked to rate Alex based on several characteristics. Those in the bright room rated him as more aggressive than those who were in the dim room.

In the same experiment, the participants were given photos of three female models and asked to judge their “sexiness.” Regardless of the participant’s gender, those in the bright room judged all three women to be “hotter” than those in the dim room.

“[This experiment] showed the participants judged ambiguously aggressive behaviour as more aggressive and potentially sexy women as sexier in bright than in dimmed light,” the researchers wrote in their paper. “Therefore, bright light polarized judgments of both positive and negative stimuli.”

spicy chicken wings

Participants in brighter rooms chose spicier chicken wing flavours than those in dim rooms. (Shutterstock)

Xu and Labroo came to similar conclusions in their other experiment: Participants in the bright room drank more of a tasty juice and drank less of an unappetizing juice. They felt even more positive about words like "flower" and "smile" and felt even more negative toward words like "medicine" or "dentist."

In one surprising experiment, Xu says participants in the bright room craved spicier foods. Xu says the idea for that test came about because the authors themselves are fans of spicy cuisine.

“We feel kind of excited when we eat spicy stuff,” Xu explained. “We were wondering: If people eat spicy food because they are seeking the excitement, like the thrill of burning their tongue, then bright light may amplify this emotion.”

After presenting participants with a menu of different flavours of chicken wings, they found that those in the bright room chose spicier sauces than those in the dim room.

“This kind of results, it’s predicted from theory, but actually getting it made me feel a little bit surprised,” said Xu.

Perceiving heat

The researchers suggest that the psychological link between light and emotion has to do with how we perceive heat.

Xu explains that in the natural sciences, brighter things are perceived by humans to be warmer — for instance, the stars.

'If you are sad to begin with, then making the environment brighter will make you even sadder.'- Alison Xu, University of Toronto Scarborough

The researchers hypothesized that if brightness serves as an input for the perception of warmth, then the bright light by itself, regardless of whether it is accompanied by heat or not, may actually induce psychological feelings of warmth. In one experiment, participants in the brighter room reported it was also warmer. 

“And then these may additionally amplify people’s default emotions — which means if you are happy, [by] turning a bright light on, you will feel happier,” Xu said. “If you are sad to begin with, then making the environment brighter will make you even sadder.”

Xu notes that their findings are solely based on the brightness of ambient light. When it comes to Seasonal Affective Disorder, a condition where people experience feelings of depression during the winter, she says that there are a number of other factors at play, such as level of activity and the amount of time spent outside.

The link between light and emotion could have a number of real-world applications. For example, Xu says that her interest in how people make decisions was one of the motivations behind the study.

“In a workplace, people may get involved in arguments because we have different opinions,” she said. “Sometimes people get emotional, but that might not be optimal for decision making in a company.”

Xu says that in those kinds of heated situations, dimming the lights may help curb strong emotions and make people more rational.

Marketers could also take note, especially those selling emotion-laden products like rings or flowers.

“You may want to make the store as bright as possible,” Xu said “You don't want to make it dimmed because it may reduce how people feel about your product.”