Pushing people to their tipping point: Phenomenal tipping point is predicted by phenomenal vertical and intuitive beliefs
Previous work has shown that people overestimate their own body tilt by a factor of about 1.5, the same factor by which people overestimate geographical and man-made slopes. In Experiment 1 we investigated whether people can accurately identify their own and others’ tipping points (TPs) – the point at which they are tilted backward and would no longer be able to return to upright – as well as their own and others’ center of mass (COM) – the relative position of which is used to determine actual TP. We found that people overestimate their own and others’ TP when tilted backward, estimate their own and others’ COM higher than actual, and that COM estimation is unrelated to TP. In Experiment 2, we investigated people’s intuitive beliefs about the TP. We also investigated the relationship between phenomenal TP and perceived vertical. Whether verbally (conceptually) estimating the TP, drawing the TP, or demonstrating the position of the TP, people believe that the TP is close to 45°. In Experiment 3, we found that anchoring influences phenomenal TP and vertical. When accounting for starting position, the TP seems to be best predicted by an intuitive belief that it is close to 45°. In Experiment 4, we show that there is no difference in phenomenal TP and vertical when being tilted about the feet or waist/hips. We discuss the findings in terms of action-perception differences found in other domains and practical implications.
KeywordsPerception and action Spatial cognition Visual perception
We would like thank Roger Swaney for designing and putting together the apparatus used in Experiment 4.
- Adolph, K. E. (2002). Learning to keep balance. In (R. Kail (Ed.), Advances in child development and behavior. (Vol. 30, pp. 1-41). Amsterdam: Elsevier Science.Google Scholar
- Baud-Bovy, G., & Gentaz, E. (2004). The visual localization of the centre of triangles in young children and adults. Current Psychology Letters, 2, 2-11.Google Scholar
- Bhalla, M., & Proffitt, D. R. (1999). Visual-motor recalibration in geographical slant perception. Journal of Experimental Psychology: Human Perception and Performance, 25, 1076– 1096.Google Scholar
- Centers for Disease Control (2016). Falls are leading cause of injury and death in older Americans. https://www.cdc.gov/media/releases/2016/p0922-older-adult-falls.html
- Ito, Y., & Gresty, M. A. (1997). Subjective postural orientation and visual vertical during slow pitch tilt for the seated human subject. Aviation, Space, and Environmental Medicine, 68, 3–12.Google Scholar
- Jewell, J. G. (1998). The misperception of body tilt: Support for an ecologically-guided multisensory representation of space. Unpublished doctoral dissertation, Kent State University.Google Scholar
- Shaffer, D. M., Maynor, A. B., Utt, A. L., Briley, B. A. (2009). Lack of conscious awareness of how we navigate to catch baseballs. In Experimental psychology research trends. (E. Hartonek, Ed.) E. B. Hauppauge: Nova Science Publishers, Inc.Google Scholar
- Shaffer, D. M., McManama, E., Swank, C., Williams, M., & Durgin, F. H. (2014). Anchoring in action: Manual estimates of slant are powerfully biased toward initial hand orientation and are correlated with verbal report. Journal of Experimental Psychology: Human Perception and Performance, 40, 1203-1212. https://doi.org/10.1037/a0036217 Google Scholar
- Shaffer, D. M., Taylor, A., Thomas, A., Graves, P., Smith, E., & McManama, E. (2016). Pitching people with an inversion table: Estimates of body orientation are tipped as much as those of visual surfaces. Attention, Perception, & Psychophysics, 78, 700-706. https://doi.org/10.3758/s13414-015-1019-x CrossRefGoogle Scholar
- Wang, F. Skubic, M., Abbott, C., & Keller, J. M. (2010). Body sway measurement for fall risk assessment using inexpensive webcams. Conference Proceedings IEEE in Engineering, Medicine and Biology Society, pp. 2225-2229. https://doi.org/10.1109/IEMBS.2010.5626100.