image: A newly-hatched Testudo hermanni tortoise looking at a face-like stimulus view more
Credit: Image credit: Gionata Stancher.
Solitary land tortoises show an early preference for face-like stimuli, according to a study of shape preferences in newly hatched reptiles. Species with parental care, including human babies, domestic chicks, and monkeys, show a preference for orienting toward face-like representations early in life. Elisabetta Versace and colleagues investigated whether the phenomenon is related to parental care or represents a general mechanism to orient toward other living beings. The authors tested the responses of Testudo land tortoises, which are solitary species that receive no parental care, to face-like stimuli. The authors posted visual stimuli on each side of a boxed arena and monitored the animals' approach. While wearing face masks to conceal their own facial features, the authors measured the response of 136 newly hatched tortoises, which had never seen the face of a human or other animals. These visually naïve tortoises responded more strongly to the standard face-like stimuli, namely three blobs arranged in an upside-down triangle, compared with other configurations. According to the authors, the predisposition of the solitary species to approach face-like stimuli likely arose in a common ancestor of mammals, birds, and reptiles and suggests a role in exploratory behavior and learning.
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ARTICLE #20-11453: "Early preference for face-like stimuli in solitary species as revealed by tortoise hatchlings," by Elisabetta Versace, Silvia Damini, and Gionata Stancher.
MEDIA CONTACT: Elisabetta Versace, Queen Mary University of London, UNITED KINGDOM; e-mail: <e.versace@qmul.ac.uk>
Journal
Proceedings of the National Academy of Sciences