【AI前沿】Whatever the mirror test tells us, beluga whales pass it

What do we see?Whatever the mirror test tells us, beluga whales pass itThe white whales join the short, contested list of animals that see themselves.Federica Sgorbissa–May 24, 2026 7:15 am|90Credit:David Merron PhotographyCredit:David Merron PhotographyText settingsStory textSizeSmallStandardLargeWidthStandardWideLinksStandardOrange Subscribers onlyLearn moreMinimize to navIn hours of underwater video footage from a New York aquarium, a beluga whale named Natasha stretches her neck, pirouettes, nods, and shakes her head in front of a two-way mirror. Her daughter Maris does much the same. According to a new study published inPLOS One, both animals show the behavioral hallmarks of mirror self-recognition—a cognitive ability long considered a marker of self-awareness, and one that had never before been documented in beluga whales.If the result holds up, belugas join a remarkably short list. The mirror self-recognition test (MSR) has been passed, with varying degrees of confidence, by humans (starting around age two), a handful of great apes (chimps, bonobos, orangutans, and—somewhat contentiously—gorillas),Asian elephants,bottlenose dolphins, probablymagpies, possiblyorcas, and, if you can believe it, acleaner wrasse. That’s it. No dogs, no cats, no monkeys. Plenty of species we had assumed were self-aware have been tested and failed.Looking at the mirrorSo what is this test, exactly, and what is it supposed to tell us?The procedure is this: While the animal isn’t looking, researchers place a mark on a spot it can only see via a reflection. A mirror is then put in front of the animal while the researchers watch. If the animal touches or examines the mark while looking at its reflection, it comprehends that the figure in the mirror is itself. The test is intuitive and easy to perform—and almost no species passes.Why is this a test of self-awareness in the first place? The logic, going back to the psychologist Gordon Gallup (who invented the test in 1970), is that to use a mirror as a tool for inspecting your own body, you need a mental representation of yourself as a distinct entity. A piece of silvered glass, in this telling, can pry open a lot of cognitive doors.Gallup himself is a tough grader. Plenty of positive results have been announced over the decades, and he’s pushed back on most of them. If an animal doesn’t show clear self-directed behavior—actively trying to touch or examine the mark—the test, in his view, fails. On that score, the beluga results sit right at the edge.Revisiting old dataThe footage is more than two decades old. “After the initial study we were hoping to conduct more studies with additional belugas over the next years but that was not possible,” senior author Diana Reiss said in an email. “Inspired by the numerous studies over the past years reporting on different aspects of beluga whale cognition and behavior, we decided to revisit and digitize the original videotapes and conduct a rigorous analysis.” Some tapes had degraded in the meantime, and portions of the original data were lost.The original experiment exposed four belugas to the mirror together, in their usual social housing. Only Natasha and Maris showed sustained interest, so only they advanced to the experimental phase, where they were marked with waterproof lipstick during feeding sessions. Because the animals were awake and could feel the application, the researchers ran sham-mark controls: the same procedure, but without the pigment. The whales only showed self-recognition-like behaviors after being actually marked.“The two beluga whales showed the same progression of behavioral stages reported for other species that show evidence of MSR,” first author Alexander Mildener said in an email. “The whales did not exhibit self-directed behaviors in the absence of the mirror or in the control condition. One of the whales also passed the mark test by demonstrating mark-directed behavior by orienting the area of her body that was temporarily marked toward the mirror.”The sample is tiny, but that’s not unusual—if even a single animal can do something, the species is in principle capable of it. The harder question is whether what Natasha and Maris did really counts. Some of the most-cited behaviors—bubble bite play, barrel rolls—are documented forms of solo play that belugas engage in even without a mirror nearby. Their increased time spent at the reflective surface is suggestive, but doesn’t rule out the possibility that the mirror was just a novel source of stimulation.The one genuinely mark-directed behavior came from Natasha, who repeatedly pressed the marked area—behind her right ear—against the mirror. Without arms, she couldn’t point. It’s the strongest data point in the study, but a softer kind of evidence than a chimp or an elephant typically delivers.Even granting that belugas pass—and given that dolphins do, and orcas plausibly do too, it wouldn’t be a shock—the more interesting question is what a result lik