The extent to which different species display self-recognition is a controversial topic in comparative cognition. Self-recognition is widely validated through the mark test in which a dye or paint mark is applied surreptitiously to the subject. Mark-directed responses in the presence of a mirror are taken as evidence of self-recognition. Over the past 50 years many different species have been administered the mark test, but only a handful have passed it. Some have suggested that species that pass the mark test are those that have a complex social structure. In this review, we propose, rather, that the reason why an animal fails the mark test is because the study has failed to adequately account for one or more of three crucial elements: mirror understanding, self-exploration, and mark saliency. Alternative methods of validating mirror self-recognition also are discussed.

不同物种表现出自我识别的程度是比较认知中一个有争议的话题。自我识别通过标记测试得到广泛验证，其中染料或油漆标记被偷偷地应用到受试者身上。在镜子面前以标记为导向的反应被视为自我识别的证据。在过去的 50 年里，许多不同的物种都通过了标记测试，但只有少数物种通过了它。有人认为，通过分数测试的物种是那些具有复杂社会结构的物种。在这篇综述中，我们提出，动物未能通过标记测试的原因是因为该研究未能充分解释三个关键要素中的一个或多个：镜像理解、自我探索和标记显着性。