Abstract
Humans and other animals are highly sensitive to deviations from bilateral symmetry and prefer symmetric mates. Fluctuating asymmetries (FAs) are random deviations from perfect symmetry that can result from developmental instability. Human perceptions of facial asymmetry are driven by FAs and insensitive to directional asymmetries (DAs), which have a consistent direction of bias (e.g., left side always larger) across the population and are unrelated to developmental stability. We hypothesized that perceptual adaptation may filter out DAs and provide a proximate mechanism for this perceptual focus on FAs. We created a small population of faces with DAs by applying a unilateral distortion to the same side of each face. After 5 min of adaptation, (new) faces with these DAs looked less asymmetric and the most symmetric-looking distortion shifted toward the adapting asymmetry level. Parallel changes occurred for attractiveness. We suggest that perceptual adaptation may provide the proximate mechanism for an evolutionarily adaptive focus on FAs.
Article PDF
References
Clifford, C. W. G., & Rhodes, G. (Eds.) (2005). Fitting the mind to the world: Adaptation and after-effects in high-level vision. Oxford: Oxford University Press.
Clifford, C. W. G., Webster, M. A., Stanley, G. B., Stocker, A. A., Kohn, A., Sharpee, T. O., & Schwartz, O. (2007). Visual adaptation: Neural, psychological and computational aspects. Vision Research, 47, 3125–3131.
Livshits, G., & Kobyliansky, E. (1991). Fluctuating asymmetry as a possible measure of developmental homeostasis in humans: A review. Human Biology, 63, 441–466.
MacLin, O. H., & Webster, M. A. (2001). Influence of adaptation on the perception of distortions in natural images. Journal of Electronic Imaging, 10, 100–109.
Mather, K. (1953). Genetic control of stability in development. Heredity, 7, 297–336.
Møller, A. P., & Swaddle, J. P. (1997). Asymmetry, developmental stability, and evolution. New York: Oxford University Press.
Møller, A. P., & Thornhill, R. (1998). Bilateral symmetry and sexual selection: A meta-analysis. American Naturalist, 151, 174–192.
Morikawa, K. (2005). Adaptation to asymmetrically distorted faces and its lack of effect on mirror images. Vision Research, 45, 3180–3188.
Palmer, A. R., & Strobeck, C. (2003). Fluctuating asymmetry analyses revisited. In M. Polak (Ed.), Developmental instability: Causes and consequences (pp. 279–319). New York: Oxford University Press.
Paras, C. L., Kaping, D., & Webster, M. A. (2004). Adaptation and the perception of facial symmetry [Abstract]. Journal of Vision, 4(8), 440a. doi:10.1167/4.8.440
Polak, M. (Ed.) (2003). Developmental instability: Causes and consequences. New York: Oxford University Press.
Rhodes, G. (2006). The evolutionary psychology of facial beauty. Annual Review of Psychology, 57, 199–226.
Rhodes, G., & Jeffery, L. (2006). Adaptive norm-based coding of facial identity. Vision Research, 46, 2977–2987.
Rhodes, G., Jeffery, L., Watson, T., Clifford, C. W. G., & Nakayama, K. (2003). Fitting the mind to the world: Face adaptation and attractiveness aftereffects. Psychological Science, 14, 558–566.
Rhodes, G., Jeffery, L., Watson, T., Jaquet, E., Winkler, C., Clifford, C. W. G. (2004). Orientation-contingent face aftereffects and implications for face-coding mechanisms. Current Biology, 14, 2119–2123.
Rhodes, G., Proffit, F., Grady, J. M., & Sumich, A. (1998). Facial symmetry and the perception of beauty. Psychonomic Bulletin & Review, 5, 659–669.
Rhodes, G., & Simmons, L. (2007). Symmetry, attractiveness and sexual selection. In R. I. M. Dunbar & L. Bartlett (Eds.), Oxford handbook of evolutionary psychology (pp. 333–364). New York: Oxford University Press.
Robbins, R., McKone, E., & Edwards, M. (2007). Aftereffects for face attributes with different natural variability: Adaptor position effects and neural models. Journal of Experimental Psychology: Human Perception & Performance, 33, 570–592.
Schwartz, O., Hsu, A., & Dayan, P. (2007). Space and time in visual context. Nature Reviews Neuroscience, 8, 522–535.
Simmons, L. W., Rhodes, G., Peters, M., & Koehler, N. (2004). Are human preferences for facial symmetry focused on signals of developmental instability? Behavioral Ecology, 15, 864–871.
Thornhill, R., & Møller, A. P. (1997). Developmental stability, disease and medicine. Biological Reviews of the Cambridge Philosophical Society, 72, 497–548.
Van Valen, L. (1962). A study of fluctuating asymmetry. Evolution, 16, 125–142.
Watson, T. L., & Clifford, C. W. G. (2003). Pulling faces: An investigation of the face-distortion aftereffect. Perception, 32, 1109–1116.
Webster, M. A., & MacLin, O. H. (1999). Figural aftereffects in the perception of faces. Psychonomic Bulletin & Review, 6, 647–653.
Zajonc, R. B. (1968). Attitudinal effects of mere exposure. Journal of Personality & Social Psychology, 9, 1–27.
Zakharov, V. M. (1981). Fluctuating asymmetry as an index of developmental homeostatis. Genetika, 13, 241–256.
Author information
Authors and Affiliations
Corresponding author
Additional information
This research was funded by a professorial fellowship from the Australian Research Council to G.R.
Rights and permissions
About this article
Cite this article
Rhodes, G., Louw, K. & Evangelista, E. Perceptual adaptation to facial asymmetries. Psychonomic Bulletin & Review 16, 503–508 (2009). https://doi.org/10.3758/PBR.16.3.503
Received:
Accepted:
Issue Date:
DOI: https://doi.org/10.3758/PBR.16.3.503