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

      Murray, Lindsay; University of Chester (American Psychological Association, 2020-03-12)
      The anomalous position of gorillas (G. g. 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 television monitor, to examine behavioural differences indicative of developing self-recognition. The behaviors of four Western lowland gorillas at Bristol Zoo, UK were observed while watching a TV screen during five 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 to 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.