Leaning to the Left Makes the Eiffel Tower Seem Smaller - Posture-Modulated Estimation

Psychological Science
December 2011 vol. 22 no. 12 1511-151
Version of Record - Dec 8, 2011

Anita Eerland, Tulio M. Guadalupe and Rolf A. Zwaan

Psychology Institute, Faculty of Social Sciences, Erasmus University Rotterdam, P.O. Box 1738, 3000 DR Rotterdam, The Netherlands

Abstract

In two experiments, we investigated whether body posture influences people’s estimation of quantities. According to the mental-number-line theory, people mentally represent numbers along a line with smaller numbers on the left and larger numbers on the right. We hypothesized that surreptitiously making people lean to the right or to the left would affect their quantitative estimates. Participants answered estimation questions while standing on a Wii Balance Board. Posture was manipulated within subjects so that participants answered some questions while they leaned slightly to the left, some questions while they leaned slightly to the right, and some questions while they stood upright. Crucially, participants were not aware of this manipulation. Estimates were significantly smaller when participants leaned to the left than when they leaned to the right.

http://pss.sagepub.com/content/22/12/1511