The optical illusion is often credited to Professor Joseph Jastrow, a pioneering psychologist, who used it to illustrate optional illusions in 1891. The same illusion was published by Felix Müller-Lyer in 1889 and by Wilhelm Wundt a year later. Psychologists often refter to it as the Jastrow-Wundt illusion of size.
This illusion has been used by psychologists to investigate how the we perceive size based on visual clues and has also been used as to test whether people with brain damage have a full field of vision. The psychological mechanism that causes this illusion is still a matter of discussion amongst researchers. The Jastrow Illusion has even been tested with chimpanzees to find out how our perception functions.
Performing the Jastrow Illusion as a magic trick requires a theatrical approach. Only showing the arcs to be swapping relative size will render it a mere puzzle. Many different variations on this theme have been published and marketed over the decades. The trick can be performed with boomerangs, fish, card fans, mud flaps or anything else that resembles an arch. Magic routines using this principle can use two, three or even four arches, adding layers of deception. When using small segments, there are also possibilities to deploy slight of hand for additional trickery.
It is often sold as part of many magic kits to children.
- Bartolomeo, P. (2014). Unilateral Spatial Neglect: Clinical Aspects. In P. Bartolomeo, Attention Disorders After Right Brain Damage (pp. 49–83). London: Springer London.
- Bateman, L. (1949). Yo-It-Chi. Abracadabra, 8(183), 214–215.
- Braine, M. D. S., & Shanks, B. L. (1965). The development of conservation of size. Journal of Verbal Learning and Verbal Behavior, 4(3), 227–242.
- Brodahl, L. A. (2015). Scripted! #1: Professors Nightmare and Fiber Optics Extended.
- Carson, R. (1965). Jimmy Lake, President, Fellowship of Ministers Convention. Linking Ring, 45(2), 111.
- Dayton, R. (1994). Fish sticks. M-U-M, 83(September), 30–32.
- de Courcy, K. (1997). A brief talk on the banana. Linking Ring, 77(1), 91–93.
- Eden, B. (1977). Magic from the “Perception” Perspective. Magic Circular, 71, 63–64.
- Freer, W. (n.d.). Boomerang Fish. In Freer’s exclusive mysteries. Miracle Factory.
- Ginn, D. (2010). Baffling boomerangs. Magicana, 57, 10–13.
- Goldston, W. (1918). An Optical Illusion. In Simple Conjuring Tricks That Anyone Can Perforn (3rd ed.). London: C. Arthur Pearson.
- Gower, H. (1962). Magic mudguards. Abracadabra, 33(833), 4–6.
- Hoy, D. (1957). The Bible and magic. Linking Ring, 37(3).
- Imai, S. (1960). Experiments on Jastrow Illusion. The Japanese Journal of Psychology, 30(5), 350–356.
- Jastrow, J. (1892). Studies from the Laboratory of Experimental Psychology of the University of Wisconsin. II. The American Journal of Psychology, 4(3), 381.
- Kaufman, R. (2016). Genii Speaks. Genii, 79(2), 10–11.
- Kleefield, J. (2008). Boomerang Teach-In. Linking Ring, 88(5), 84–85.
- Maniatis, L. M. (2008). The Leaning Tower illusion is not a simple perspective illusion. Perception, 37(11), 1769–1772.
- Massironi, M., Antonucci, G., Pizzamiglio, L., Vitale, M. V., & Zoccolotti, P. (1988). The Wundt-Jastrow illusion in the study of spatial hemi-inattention. Neuropsychologia, 26(1), 161–166.
- Müller-Lyer, F. C. (1889). Optische Urteilstauschungen. Archiv Für Anatomie Und Physiologie, (Supplement), 263–270.
- Pecor, C. J. (2001). The boomerangs revisited. Linking Ring, 81(5), 108–109.
- Piccardi, L., Palermo, L., Nori, R., Giusberti, F., & Guariglia, C. (2012). Landmark recognition and mental route navigation disorders in patients with imagery neglect and perceptual neglect. In Y. Spiteri & E. M. Galea (Eds.), Psychology of neglect (pp. 81–103). Hauppauge, N.Y: Nova Science Publishers.
- Pick, D. F., & Pierce, K. A. (1993). Theoretical parallels between the Ponzo illusion and the Wundt-Jastrow illusion. Perceptual and Motor Skills, 76(2), 491–498.
- Price, D. (2000). Color changing boomerangs. M-U-M, 89(May), 36–38.
- Society of Indian Magicians. (1947). Spell of India. Linking Ring, 27(10), 64–65.
- Solomon, E. (n.d.). Tales Worth Telling.
- Spragg, B. (1959). Hocus Pocus Parade. Linking Ring, 38(11), 43–46.
- Sweigard, M. (1968). The two banana illusion. Linking Ring, 48(1), 72–73.
- Thurston, Howard (1927) Which Is Larger?. In 200 More Tricks You Can Do.
- Tomonaga, M. (2015). Fat Face Illusion, or Jastrow Illusion with Faces, in Humans but not in Chimpanzees. I-Perception, 6(6).
- Tronick, E., & Hershenson, M. (1979). Size-distance perception in preschool children. Journal of Experimental Child Psychology, 27(1), 166–184.
- von Weber, H. (1940). Money from magic. Linking Ring, 20(4), 302–305.
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Peter Prevos, The Jastrow Illusion in Magic