Video-mediated behavior in gorillas (gorilla gorilla gorilla): A stage in the development of self-recognition in a juvenile male?

Abstract

The anomalous position of gorillas (Gorilla gorilla gorilla) in the capacity for self-recognition remains puzzling. The standard measure of self-recognition is Gallup's (1970) mark test that assesses an individual's ability to recognize its altered image in a mirror following the application of paint marks to visually inaccessible areas. Here, the results of a small-scale pilot study are presented, utilizing video playback through a TV monitor, to examine behavioral differences indicative of developing self-recognition. The behaviors of 4 Western lowland gorillas at Bristol Zoo, United Kingdom, were observed while watching a TV screen during 5 conditions: blank screen, white noise interference, footage of unfamiliar gorillas, self previously recorded, and self-live. Differences were predicted in the frequency of the gorillas' observed behaviors when viewing each of the conditions: specifically, that there would be more visual inspection, contingent body and facial movements, and self-exploration in the self-recorded and self-live conditions compared with the other conditions. These predictions were partially supported. No agonistic or fear responses were observed, and self-exploration was only seen in the self-live condition. During live playback, contingency-checking movements and self-exploration of the mouth were observed, particularly in the youngest gorilla, providing important video evidence of a close parallel to the mouth exploratory behavior witnessed in self-recognizing chimpanzees. On the basis of these preliminary findings of differentiated spontaneous behaviors, a tentative framework is proposed for categorizing gorillas according to levels of developing self-recognition along a continuum. (PsycInfo Database Record (c) 2020 APA, all rights reserved).