Mirror self-recognition in gorillas (Gorilla gorilla gorilla): A review and evaluation of mark test replications and variants
Affiliation
University of Chester; Kyoto University Graduate School of Letters; University at Albany, State University of New YorkPublication Date
2022-01-07
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Mirror self-recognition (MSR), widely regarded as an indicator of self-awareness, has not been demonstrated consistently in gorillas. We aimed to examine this issue by setting out a method to evaluate gorilla self-recognition studies that is objective, quantifiable, and easy to replicate. Using Suarez and Gallup’s (1981) study as a reference point, we drew up a list of 15 methodological criteria and assigned scores to all published studies of gorilla MSR for both methodology and outcomes. Key features of studies finding both mark-directed and spontaneous self-directed responses included visually inaccessible marks, controls for tactile and olfactory cues, subjects who were at least five years old, and clearly distinguishing between responses in front of versus away from the mirror. Additional important criteria include videotaping the tests, having more than one subject, subjects with adequate social rearing, reporting post-marking observations with mirror absent, and giving mirror exposure in a social versus individual setting. Our prediction that MSR studies would obtain progressively higher scores as procedures and behavioural coding practices improved over time was supported for methods, but not for outcomes. These findings illustrate that methodological rigour does not guarantee stronger evidence of self-recognition in gorillas; methodological differences alone do not explain the inconsistent evidence for MSR in gorillas. By implication, it might be suggested that, in general, gorillas do not show compelling evidence of MSR. We advocate that future MSR studies incorporate the same criteria to optimize the quality of attempts to clarify the self-recognition abilities of gorillas as well as other species.Citation
Murray, L. E., Anderson, J. R. & Gallup, G. G., Jr. (2022). Mirror self-recognition in gorillas (Gorilla gorilla gorilla): A review of mark test replications and variants. Animal Cognition, 25, 783–792. https://doi.org/10.1007/s10071-021-01592-3Publisher
SpringerJournal
Animal CognitionAdditional Links
https://link.springer.com/article/10.1007/s10071-021-01592-3Type
ArticleDescription
This version of the article has been accepted for publication, after peer review (when applicable) and is subject to Springer Nature’s AM terms of use, but is not the Version of Record and does not reflect post-acceptance improvements, or any corrections. The Version of Record is available online at: http://dx.doi.org/10.1007/s10071-021-01592-3ISSN
1435-9448EISSN
1435-9456Collections
Except where otherwise noted, this item's license is described as https://creativecommons.org/licenses/by-nc-nd/4.0/
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