#Chimpanzee face front view download#

Most non-human female primates, chimpanzees included, show a swelling and reddening of the anogenital region around the time of ovulation. Previous research has shown that in recognizing each other, chimpanzees do not rely on the face alone, but also easily recognize each other by their behinds.

Intriguingly, previous studies included almost all body parts, except the most obvious one, which is the behind, as we will outline below. Thus, effects of inversion have been observed for faces and whole bodies, but are generally not found for individual body parts. The face inversion effect has been observed in chimpanzees too, and although not all chimpanzees show this effect at all times, overall there is evidence that configural processing is a critical element of efficient face detection in chimpanzees as well.

Conclusive evidence has shown that this effect is primarily due to a disruption in the processing of configural, rather than featural, information in faces. Importantly, their recognition is disproportionally impaired, relative to objects such as houses or cars, when they are seen inverted rather than upright. Humans have specialized brain areas to recognize faces and whole bodies and their expertise in face recognition is demonstrated by the ‘inversion effect’, showing that faces and whole bodies, but not objects, are recognized configurally rather than by their parts. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.Ĭompeting interests: The authors have declared that no competing interests exist.įor group-living animals, primates included, the recognition of conspecifics is crucial for their survival. įunding: This work was supported by the Japan Society for the Promotion of Science (pE10084 and BR120105), the Nederlandse Organisatie voor Wetenschappelijk Onderzoek (#016-155-082) and the Dobberke Foundation for Comparative Psychology Koningklijke Nederlandse Akademie van Wetenschappen (UPS/BP/5215) awarded to MEK, and JSPS-KAKENHI (20002001, 23220006, 24000001 and 15H05709) to MT.

#Chimpanzee face front view download#

This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.ĭata Availability: The SPSS data file is freely available to download here. Received: JAccepted: OctoPublished: November 30, 2016Ĭopyright: © 2016 Kret, Tomonaga. PLoS ONE 11(11):Įditor: Nouchine Hadjikhani, Harvard Medical School, UNITED STATES Species-Specific Inversion Effects for Faces and Behinds in Humans and Chimpanzees ( Pan Troglodytes). The findings suggest an evolutionary shift in socio-sexual signalling function from behinds to faces, two hairless, symmetrical and attractive body parts, which might have attuned the human brain to process faces, and the human face to become more behind-like.Ĭitation: Kret ME, Tomonaga M (2016) Getting to the Bottom of Face Processing. In four different delayed matching-to-sample tasks with upright and inverted body parts, we show that humans demonstrate a face, but not a behind inversion effect and that chimpanzees show a behind, but no clear face inversion effect.

We hypothesized that chimpanzees process behinds configurally in a way humans process faces. This provides an important socio-sexual signal for group members, who can identify individuals by their behinds. Chimpanzee females show a swelling and reddening of the anogenital region around the time of ovulation. The human face, with its distinct features such as eye-whites, eyebrows, red lips and cheeks signals emotions, intentions, health and sexual attraction and, as we will show here, shares important features with the primate behind. As demonstrated by the ‘face inversion effect’, humans are experts in recognizing faces and unlike objects, recognize their identity by processing it configurally. For social species such as primates, the recognition of conspecifics is crucial for their survival.