Descent Illusion, The
The Descent Illusion is the tendency to overestimate a vertical height more while standing on top of it than while standing at its bottom. Predicted from Evolved Navigation Theory to have evolved in response to greater falling risks on descent than ascent, it is ostensibly the largest known distance illusion.
I predicted the Descent Illusion from my Evolved Navigation Theory (Jackson 2005; Evolved Navigation Theory, this volume). Evolved Navigation Theory specifies how natural selection can result from navigational consequences.
The Descent Illusion
A major source of selection resulting from navigational consequences over evolutionary time is the act of falling, which continues to kill and injure modern humans more broadly than any other accidental source (Verma et al. 2016). One predictor of the likelihood and severity of falling is the direction of travel, where descent results in falls more often and more severe than ascent (see Jackson and Cormack 2007).
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- Jackson, R. E. (2017). Measuring the generalizability of virtual-reality. Manuscript under review at Psychological Science. Google Scholar
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- Jackson, R. E., & Gómez de García, J. (2017). Evolved navigation illusion provides universal human perception measure. Journal of Vision, 17(1):39, 1–5. https://doi.org/10.1167/17.1.39
- Jackson, R. E., & Willey, C. R. (2011). Evolved navigation theory and horizontal visual illusions. Cognition, 119, 288–294. https://doi.org/10.1016/j.cognition.2010.11.003.
- Jackson, R. E., Willey, C. R., & Cormack, L. K. (2013). Learning and exposure affect environmental perception less than evolved navigation costs. PLoS One, 8(4), e59690. https://doi.org/10.1371/journal.pone.0059690.
- Verma, S. K., Willetts, J. L., Corns, H. L., Marucci-Wellman, H. R., Lombardi, D. A., & Courtney, T. K. (2016). Falls and fall-related injuries among community-dwelling adults in the United States. PLoS One, 11(3), e0150939. https://doi.org/10.1371/journal.pone.0150939.