正式称为“镜像自我识别”测试或MSR测试的“镜像测试”是由Gordon Gallup Jr.博士于1970年发明的。生物心理学家盖洛普创建了MSR测试来评估动物的自我意识 – 更具体地说，动物是否在视觉上能够在镜子前识别自己。盖洛普认为，自我认知可以被认为是自我意识的同义词。如果动物在镜子中认出自己，盖洛普假设，他们可以被认为有能力进行内省。测试的工作原理如下：首先，将被测试的动物置于麻醉状态，以便以某种方式标记其身体。标记可以是从身体贴纸到彩绘面部的任何东西。这个想法很简单，标记需要位于动物在日常生活中通常无法看到的区域。例如，猩猩的手臂不会被标记，因为猩猩可以在不看镜子的情况下看到它的手臂。相反，将标记像脸部的区域。动物从麻醉中醒来后，现在标记，它被给了一面镜子。如果动物以任何方式接触或以其他方式检查自己的身体，它会“通过”测试。根据盖洛普的说法，这意味着动物知道反射的图像是它自己的图像，而不是另一种动物。更具体地说，如果动物在镜子中观察时比在镜子不可用时更接触标记，则意味着它识别自身。盖洛普假设大多数动物会认为这个图像是另一只动物的图像并且“失败”了自我识别测试。然而，MSR测试并非没有批评。对该测试的最初批评是它可能导致假阴性，因为许多物种不是视觉导向的，并且更多的物种在眼睛周围有生物限制，例如狗，它们不仅更有可能使用他们的听觉和嗅觉导航世界，但也将直接目光接触视为侵略。例如，大猩猩也不愿意与眼睛接触，并且不会花太多时间照镜子来认识自己，这被认为是为什么他们中的许多人（但不是所有人）都没有通过镜子测试的原因。另外，已知大猩猩在感觉到被观察时会有一些敏感反应，这可能是他们的MSR测试失败的另一个原因。对MSR测试的另一个批评是，一些动物本能地对他们的反思反应很快。在大多数情况下，动物对镜子采取积极行动，将其反射视为另一种动物（以及潜在的威胁。）这些动物，如一些大猩猩和猴子，将无法通过测试，但这也可能是假阴性，但是，因为如果这些灵长类动物等聪明的动物花更多的时间考虑（或有更多时间考虑）反射的意义，它们可能会通过。此外，已经注意到一些动物（甚至可能是人类）可能找不到足够的标记来研究它或对它作出反应，但这并不意味着它们没有自我意识。这方面的一个例子是在三只大象上进行的MSR测试的特定实例。一只大象过去但其他两只大象失败了。然而，失败的两个仍然表现出他们认可自己的方式，研究人员假设他们只是对标记不够关心，或者对标记没有足够的关注。对该测试的最大批评之一是，仅仅因为动物能够在镜子中识别自己并不一定意味着动物在更有意识的心理基础上具有自我意识。
The “Mirror Test,” officially called the “Mirror Self-Recognition” test or MSR test, was invented by Dr. Gordon Gallup Jr. in 1970. Gallup, a biopsychologist, created the MSR test to assess the self-awareness of animals — more specifically, whether animals are visually able to recognize themselves when in front of a mirror. Gallup believed that self-recognition could be considered synonymous with self-awareness. If animals recognized themselves in the mirror, Gallup hypothesized, they could be considered capable of introspection. The test works as follows: first, the animal being tested is put under anesthesia so that its body can be marked in some way. The mark can be anything from a sticker on their body to a painted face. The idea is simply that the mark needs to be on an area that the animal can’t normally see in its day-to-day life. For example, an orangutan’s arm wouldn’t be marked because the orangutan can see its arm without looking at a mirror. An area like the face would be marked, instead. After the animal wakes up from the anesthesia, now marked, it is given a mirror. If the animal touches or otherwise examines the mark in any way on its own body, it “passes” the test. This means, according to Gallup, that the animal understands that the image reflected is its own image, and not another animal. More specifically, if the animal touches the mark more when it is looking in the mirror than when the mirror is not available, it means it recognizes itself. Gallup hypothesized that most animals would think the image was that of another animal and “fail” the self-recognition test. The MSR test hasn’t been without its critics, however. An initial criticism of the test is that it may result in false negatives, because many species are not visually-oriented and many more have biological constraints around eyes, such as dogs, which are not only more likely to use their hearing and sense of smell to navigate the world, but who also view direct eye-contact as aggression. Gorillas, for example, are also averse to eye contact and wouldn’t spend enough time looking in a mirror to recognize themselves, which has been posited as a reason why many of them (but not all of them) fail the mirror test. Additionally, gorillas are known to react somewhat sensitively when they feel they are being observed, which may be another reason for their MSR test failure. Another criticism of the MSR test is that some animals respond very quickly, on instinct, to their reflection. In most cases, animals act aggressively toward the mirror, perceiving their reflection as another animal (and a potential threat.) These animals, such as some gorillas and monkeys, would fail the test, but this may also be a false negative, however, because if intelligent animals such as these primates took more time to consider (or were given more time to consider) the meaning of the reflection, they might pass. Additionally, it has been noted that some animals (and perhaps even humans) may not find the mark unusual enough to investigate it or react to it, but this doesn’t mean they have no self-awareness. One example of this is a specific instance of the MSR test done on three elephants. One elephant passed but the other two failed. However, the two that failed still acted in a way that indicated they recognized themselves and researchers hypothesized that they just didn’t care enough about the mark or weren’t concerned enough about the mark to touch it. One of the biggest criticisms of the test is that just because an animal can recognize itself in a mirror does not necessarily mean the animal is self-aware, on a more conscious, psychological basis.