In the late 1920s, Elton Mayo, an Australian-born sociologist and a manager at Western Electric’s Hawthorne plant in Chicago, US, was keen on improving the productivity of assembly line workers at the factory. Unknown to the workers, Mayo turned up the workplace illumination for half of the workers (the treatment group) and left it unchanged for the other half (the controlled group). He found that the productivity of the treatment group shot up dramatically as compared to the control group, and thus concluded that better illumination increases productivity.

The Hawthorne experiments came to be considered one of the earliest studies in management science, and gave birth to the Hawthorne effect — the alteration of behaviour by the subjects of a study due to their awareness of being observed.

Apart from lighting, Mayo’s research team also conducted other randomized experiments, including manipulation of working hours, rest breaks, etc, but soon realised that the productivity improvements seen with each change tended to peter out over time. Researchers soon realised that it was not changes in lighting or any other ambient parameter that actually affected productivity, but the very act of making a change did the trick.

While the illumination changes in the Hawthorne experiments had only transient effects on worker productivity, marketers have realised that consumer behaviour in retail or restaurant environments may be non-trivially affected by ambient lighting. Imagine you are a retail store manager or a restaurant boss, should you pay attention to your ambient lighting, or should you keep fiddling about with it, like Mayo did?

Experiments by Brian Wansink and Koert Van Ittersum (2012) found that diners tended to eat lesser when ambient lighting was dimmed, and music was softened in a restaurant, without compromising on either satisfaction ratings or amount of money spent. This is a win-win for restaurants — dimming the lights can significantly enhance the consumer experience without affecting the bottomline.

However, a recently published study by Dipayan Biswas and colleagues indicates that matters need not be so simple. Biswas and Co ran field experiments in branches of an actual restaurant chain, two of which were randomly selected to be dimly lit, while the other two were brightly illuminated, not unlike the Hawthorne experiments of the 1920s.

However, unlike in the Hawthorne experiments, which tested the outcome of lighting on productivity, here the behaviour of interest was the choice of healthy or unhealthy food, a one-time decision compared to the more long-term measurement of productivity that Mayo was interested in.

In Biswas and Co’s experiments, people in the dimly lit restaurants tended to order more unhealthy food, like steaks, while people in the brightly lit restaurants, on average, tended to order healthier options like baked fish and vegetables. The same results were replicated in lab settings as well, where restaurant environments were simulated in controlled settings. The reason proffered for this is that bright lights make us humans more alert, and we are thus more conscious of our consumption choices.

These results have implications not just for restaurateurs, but for retailers as well as consumers in our day to day lives. Though further studies in retail conditions need to be conducted, initial intuition suggests that such lighting effects may occur in shops and supermarkets as well. Thus, an organic food chain — which in any case depends on its customers making healthy choices — may further nudge people towards buying healthy items by turning up the lighting.

Meanwhile, places like ice cream parlours, fast food joints, etc, may have a tougher decision to make — that of balancing the hedonic expectations of their consumers with their own responsibility as stakeholders in their customers’ well-being.

As for you — the reader — the implications are simple: If you are on a diet, or want to watch what you eat, just go to a brightly lit restaurant, and your food choices may just be healthier!

Read other Anchors and Prospects articles.

Lead visual: Angela Anthony Pereira

This column is intended to showcase interesting academic research in marketing. The technically oriented reader is encouraged to read the original research articles cited in the column.

Prithwiraj Mukherjee is Assistant Professor of Marketing, IIM Bangalore. Views are personal.

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