Exploring the roles of physical effort and visual salience within the proximity effect

Abstract

Background: Recent work has explored the effectiveness of the Proximity Effect, where increasing the physical distance between consumer and snacks reduces intake. Foods requiring less effort to attain, or being more visually appealing, are seen to be consumed more. Relatedly, perceived effort and visual salience are suggested mechanisms for the proximity effect, but no prior studies have directly manipulated these in association with the effect. Two between-subjects studies conducted in university laboratories are presented.

Method: Twenty chocolate brownies that were either wrapped or unwrapped (Study 1, N = 85), or 250g of M&M's, either colourful or plain brown (Study 2, N = 80), were presented as effort and salience manipulations respectively to participants at either 20 cm or 70 cm. Consumption was measured as 'likelihood of consumption' (Yes/No) and 'actual consumption' (units/grams). Potential moderating variables including perceived effort and perceived visual salience were also measured.

Results: Likelihood of consumption was positively predicted by perceived visual salience in both Studies, and by distance in Study 2. Significant main effects of distance, p < .001, ȵ² = 0.102 (20 cm > 70 cm), effort, p < .001, ȵ² = 0.089 (unwrapped > wrapped), and distance × effort interaction, p = .003, ȵ² = 0.111, were observed in Study 1 for actual consumption. A main effect of distance was found in Study 2 for actual consumption, p < .001, ȵ² = 0.062 (20 cm > 70 cm). Perceived visual salience positively correlated with actual consumption in both Studies.

Conclusions: Increasing physical effort and placing snacks further away appear to act independently and interactively to reduce snack consumption. Manipulating snack colour does not appear to influence consumption, whereas perceptions of visual salience appear to influence consumption. As such, perceived visual salience and physical effort are thought to be key mechanisms underpinning the proximity effect.

Pre-registration: Both Studies were pre-registered on the Open Science Framework (Study 1: 10.31234/osf.io/rmnys; Study 2: 10.31234/osf.io/u8bsz).

Keywords: Choice architecture; Effort; Food consumption; Nudging; Proximity; Salience.