Abstract
When two identical faces are aligned vertically, humans readily perceive the face at the bottom to be fatter than the top one. This phenomenon is called the fat face illusion. Furthermore, an apparent similarity has been pointed out between the fat face illusion and the Jastrow illusion. Recent studies have suggested the importance of facial contours and the role of basic-level processing of faces. In the present study, we directly compared the typical Jastrow illusion and fat face illusion in humans and chimpanzees using the same task. Both humans and chimpanzees clearly showed the Jastrow illusion, but only humans perceived the face at the bottom as fatter than the top. Although further examination is necessary, these results might reflect different processing levels of faces between the two species.
Highlights
When two identical faces are aligned vertically, humans readily perceive the face at the bottom to be fatter than the top one
The first was demonstrated by Thompson (2010; Thompson & Wilson, 2012) and called the fat face thin illusion: An inverted face is perceived as thinner than an upright face
The second was reported by Araragi, Aotani, and Kitaoka (2012): An upright face is underestimated in size when compared with an inverted face
Summary
When two identical faces are aligned vertically, humans readily perceive the face at the bottom to be fatter than the top one. Jastrow illusion, face perception, chimpanzees, comparative cognition Several types of illusions concerning face width or size have been reported.
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
