Garnett and colleagues studied how physical distance can nudge people toward particular food choices in cafeterias; using design to encourage specific behaviors is frequently discussed, for example, in the context of supporting healthier living. The Garnett-lead team reports that they “undertook two experimental studies involving 105,143 meal selections in the cafeterias of a British university. Placing vegetarian options first on the counter consistently increased their sales when choices were widely separated (>1.5 m; vegetarian sales as a percentage of total meal sales increased by 4.6 and 6.2 percentage points) but there was no evidence of an effect when the options were close together (<1.0 m). This suggests that order effects depend on the physical distance between options.” Even more concretely: vegetarian sales increased a statistically significant amount when vegetarian meals were placed so that diners reached them before non-vegetarian options and the spacing between entrees was extended by one meter (sales increased with an 181 cm gap but not one of 85 cm).
Emma Garnett, Theresa Marteau, Chris Sandbrook, Mark Pilling, and Andrew Balmford. 2020. “Order of Meals at the Counter and Distance Between Options Affect Student Cafeteria Vegetarian Sales.” Nature Food, vol. 1, pp. 485-488, https://doi.org/10.1038/s43016-020-0132-8