Size, weight, and expectations

Journal Article (2022)
Author(s)

Jeroen B J Smeets (Vrije Universiteit Amsterdam)

Kim Vos (Vrije Universiteit Amsterdam)

Emma Abbink (Vrije Universiteit Amsterdam)

M. A. Plaisier (Eindhoven University of Technology, TU Delft - Human Technology Relations)

Research Group
Human Technology Relations
Copyright
© 2022 Jeroen B.J. Smeets, Kim Vos, Emma Abbink, M.A. Plaisier
DOI related publication
https://doi.org/10.1177/03010066221087404
More Info
expand_more
Publication Year
2022
Language
English
Copyright
© 2022 Jeroen B.J. Smeets, Kim Vos, Emma Abbink, M.A. Plaisier
Research Group
Human Technology Relations
Issue number
5
Volume number
51
Pages (from-to)
344-353
Reuse Rights

Other than for strictly personal use, it is not permitted to download, forward or distribute the text or part of it, without the consent of the author(s) and/or copyright holder(s), unless the work is under an open content license such as Creative Commons.

Abstract

The size-weight illusion is well-known: if two equally heavy objects differ in size, the large one feels lighter than the small one. Most explanations for this illusion assume that because the information about the relevant attribute (weight itself) is unreliable, information about an irrelevant but correlated attribute (size) is used as well. If such reasoning is correct, one would expect that the illusion can be inverted: if size information is unreliable, weight information will be used to judge size. We explored whether such a weight-size illusion exists by asking participants to lift Styrofoam balls that were coated with glow in the dark paint. The balls (2 sizes, 3 weights) were lifted using a pulley system in complete darkness at 2 distances. Participants reported the size using free magnitude estimation. The visual size information was indeed unreliable: balls that were presented at a 20% larger distance were judged 15% smaller. Nevertheless, the judgments of size were not systematically affected by the 20% weight change (differences < 0.5%). We conclude that because the weight-size illusion does not exist, the mechanism behind the size-weight illusion is specific for judging heaviness.