Lighting could influence risky behaviour

Researchers from Flinders University have investigated whether the type of lighting used by casinos has an impact on gambling behaviour. Their findings indicate that circadian photoreception — the body’s non-visual response to light — could be playing an unexpected role in shaping risky decisions.

The scientists examined participants’ economic decisions using a series of casino scenarios under blue-enriched and blue-depleted light to assess the impact of light wavelengths on risk preferences.

“We found that light with more blue wavelengths in it, which is frequently emitted by LED screens and casino lighting, could subtly influence how people perceive losses and gains,” said lead author Dr Alicia Lander from FHMRI Sleep Health.

“This raises questions about the role of lighting in environments like casinos or online gambling platforms.”

While examining the study participants, the researchers manipulated the “melanopic” brightness of light, which targets the body’s internal clock, while keeping visual brightness constant.

The results showed that participants exposed to blue-enriched light became less sensitive to losses, making them more likely to choose risky financial options over safer alternatives.

“Typically, people have a strong tendency to avoid losses, often outweighing potential gains in their decision-making,” Lander said.

“However, under blue-enriched light that stimulates non-visual circadian photoreceptors, they demonstrated a reduced sensitivity to financial losses that may influence gambling tendencies, potentially encouraging riskier behaviours.

Lander added: “Under conditions where the lighting emitted less blue, people tended to feel a $100 loss much more strongly than a $100 gain — the loss just feels worse.

“But under bright, blue-heavy light such as that seen in casino machines, the $100 loss didn’t appear to feel as bad, so people were more willing to take the risk.”

The study suggests that blue light alters neural processing in brain regions tied to reward and decision-making, such as the amygdala and habenula, possibly dampening negative emotions associated with losses.

“Interestingly, we found that women displayed greater loss aversion than men, showing more reluctance to take risks under both light conditions,” Lander said.

With modern casinos, gambling machines and even smartphones using blue-heavy LED displays, the Flinders research raises questions about whether lighting could increase risk-taking behaviour in real-world gambling scenarios.

Senior researcher Professor Sean Cain said that as online gambling continues to surge, reducing blue light exposure could be a potential strategy to mitigate impulsive gambling.

“Our study provides new insights into how light influences decision-making in financial risk scenarios and raises important ethical considerations,” he said.

“Under light with more blue wavelengths, people may be less able to accurately judge risk and reward due to a decreased cognitive sensitivity to loss.

“It is possible that simply dimming the ‘blue’ in casino lights could help promote safer gambling behaviours.”

The researchers acknowledged that while the study used reliable methods and a robust design, the sample size was small (repeated testing in 15 adults) and that more research is needed to explore the relationship between light and risk taking in gambling scenarios.

The study, ‘Circadian photoreception influences loss aversion’, by Alicia C. Lander, Malisa T. Burge, Brianna G. Thomas, Andrew J. K. Phillips, Elise M. McGlashan & Sean W. Cain has been published in the Nature’s Scientific Reports journal. DOI: 10.1038/s41598-025-97370-z

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