Want to fall down the Internet rabbit hole? Look up videos of the “animal mirror test.”

Each has the same premise: Animals — domesticated, wild, doesn’t matter — encounter their own reflections, likely for the first time. In one, a gorilla pounds the ground and then barrels towards the mirror. In another, a chimpanzee spreads her lips and examines the inside of her mouth. In still another, a confused house cat playfully paws at the reflection and then examines behind the mirror.

Beyond mere time-killing entertainment, researchers believe that these mirror tests give humans insight into an animal’s sense or lack of self-awareness, a concept that human babies can comprehend between the ages of 18 and 24 months. Only a few animals — some great apes, elephants, dolphins and magpies — can make this distinction.

Or so some researchers believe. Among the naysayers is biologist and ethicist Frans de Waal, who argues in his new book “Are We Smart Enough to Know How Smart Animals Are?” that the mirror tests and others mainly expose the limitations that humans have in understanding animal intelligence.

The study of animal cognition has been separated into two camps over the last century, limiting the field, writes de Waal. One camp believed that animals were “stimulus-response machines out to obtain rewards and avoid punishment,” while the other believed that they were merely “robots genetically endowed with useful instincts.” These theories only bolstered the belief that man was unique in the animal world — and did not bode well for the design of meaningful tools to test animal intelligence.

That is until American psychologist Gordon Gallup designed the mirror test in 1970 — an idea he came up with while shaving. The test consists of placing a mark on an anesthetized ape, so that the ape is not aware of the mark. When the ape awakes, a mirror is placed in front of him. If the ape touches or tries to remove the mark, this is evidence that he recognizes himself — and that he can differentiate between “self” and “non-self,” a sophisticated sign of self-awareness. This did not fit in with the robot-or-machine animal-cognition model.

“Lumping humans in with the apes so as to elevate the hominoids as a group to a different mental level than the rest of the animal kingdom didn’t go over well. It diluted humanity’s special status,” de Waal writes.

But over the last few decades, the field has advanced as researchers have worked to adapt their tests to fit their subjects, calling into question many of the traits we consider unique to man. Studies show that rats may experience regret, crows and octopi use tools, elephants have a social-networking hierarchy that resembles our use of Facebook and whales “speak” in regional dialects.

Sheep, a cliched image of slack-jawed conformity, can remember up to 25 sheep faces — and retain that knowledge for two years, according to a 2001 paper published in Nature with the subhead: “Sheep are not so stupid after all.”

Chimps display an uncanny recall for series of numbers. One chimp Ayumu can recall a random series of numbers from one to nine, even when the number is flashed on screen for a fraction of a second. He even beat out British memory champion Ben Pridmore — and would most likely beat you, too.

“Nothing is off-limits anymore, not even rationality that was once considered humanity’s trademark,” writes de Waal.



Studies show that rats may experience regret, crows and octopi use tools, elephants have a social-networking hierarchy that resembles our use of Facebook and whales “speak” in regional dialects.

De Waal even suggests that humans might not be smart enough to know how to best test animal IQ. Take the mirror test for example.

For years researchers believed that elephants failed the mirror test. But the problem wasn’t the elephant, it was the research design. The mirrors were too small and were angled down so that the elephants only saw their feet. Researchers did not think like an elephant. When researchers retested the study at the Bronx Zoo with an 8-foot mirror set close enough to the enclosure, the results were strikingly different. This time, Happy the elephant recognized her reflection and repeatedly rubbed off the white mark placed above her left eye.

The same thing happened with gorillas. Because gorillas view eye contact as threatening, gorillas mainly shied away from the mirror or attacked it. When researchers used the mirror test on Koko, a gorilla raised in captivity in California and exposed to mirrors at a young age, she used the mirror as a tool to groom herself.

There are other issues, too, de Waal and others point out. Some animals will never be interested enough in the mirror to engage, so it will be impossible to test. Others, like dogs, use their noses more than their eyes, so they’d be less likely to pass. He points out that if dogs and cats didn’t recognize themselves in the mirror, “we would not be able to have mirrors in our homes.” He proposes that they’ve learned “to ignore their reflection.”

But what if animals did the opposite and became as obsessed with their images as we are?

“The next frontier will be to see if animals care about the mirror image to the point of embellishing themselves,” writes de Waal, “the way we do with makeup, earrings and the like. Does the mirror induce vanity? Would any species other than ours be prone to take selfies if they could?”