This research probably won’t settle the age-old rivalry between dog and cat owners, but it does come with an Oxford pedigree. Scientists at the prestigious British university say canines are definitively more intelligent than cats. Their reasoning is simple: Dogs are more social animals, so they’ve developed bigger brains than their feline counterparts. Man’s best friend, in addition to always being in a good mood, can recognize images of itself and pick up nonverbal cues.
Bigger than most, and smarter than most, too: Elephants back up their brawn with surprising prowess in numerical abilities, among other skills. Faced with experiments testing their ability to differentiate numerical amounts, like recognizing the difference between one and two items compared with the difference between five and six, elephants performed better than primates—and even human children. “Their abilities don’t seem to be limited in quite the same way as monkeys, apes, and children would be,” said the experiment’s lead researcher. Still not impressed? Elephants have been shown to tell the difference between various human languages, too.
Climate change is pushing these two species together into a battle for resources and wits—and most scientists’ money is on the grizzlies, whose stronger teeth and skulls will help them win a potential battle for scarce food. Disappearing Arctic ice, on which polar bears depend for hunting, will force them to turn to vegetarian food sources—something grizzlies are better designed to do. Grizzlies also have been found to have the largest and most complex brains of any land mammal relative to their size; they can recognize other animals they’ve seen as long as 20 years before. But don’t count out polar bears: There’s no scientific agreement on which species has the higher IQ, but some researchers believe polar bears have an intelligence roughly equal to the smartest primates.
But they both outdo humans in some cases: In an experiment designed to test why humans make investment mistakes, researchers proved that rats and pigeons are able to learn an optimal strategy and stick to it—while humans tend to second-guess themselves and show misguided confidence. Rats, however, can go one step further than their feathered friends. In another study where rats where given a choice to opt out of a test if they didn’t know the answer, they did so, “which suggests that rats, like monkeys, but unlike pigeons, may be aware of what they do,” according to the researcher.
Cephalopods—mollusks with arms, like squids and octopuses—are probably the smartest invertebrates. Octopuses are particularly bright: They have large brains relative to their body weight and have complex lobes, similar to that of mammals, allowing them to process complex information. That makes them smarter than most fish, and even smarter than some birds. They can learn to recognize shapes, open jars with screw lids and devise complex, multi-dimensional responses to attacks or challenging hunting situations. Some giant octopuses can even open child-proof medicine bottles and dramatically improve their time with practice. Popular notions about fish memories lasting only a few seconds are myths, but most of them have much smaller brains and less complex intelligence than cephalopods.
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Horses represented the proletariat in George Orwell’s Animal Farm, while the cows were mistreated, but how do they fall in the animal IQ hierarchy? Once thought to be dumb, horses at least rank higher than cows, which certainly makes them less likely to be eaten. Oregon State animal scientist Steve Davis cautioned that “the smarter we think animals are, the more humanly we care for them.” Despite the public perception that cows are dumb, a 2005 study proved that cows are, in fact, moody and feel pain, anxiety, and fear, and are intensely sexual.
The tortoise may have worn the race, but he might be one of the few smart turtles, at least according to some scientists. Dr. George Zug of the Smithsonian Institute says that “overall, turtles are pretty dumb,” although they do have some areas where they shine. They’re better at mazes than white rats, which are generally perceived as superior. Aside from white rats’ inability to run mazes, rats are generally considered one of the most intelligent animals, despite their bad reputation. A 2007 study by the University of Georgia found that lab rats are the only non-primate animal with the ability of metacognition, or reasoning and thinking based their own thought.
Chimps long held the highest position at the top of animal intelligence, but there have been a few studies knocking that notion down. Chimps are generally perceived to be as smart as 3-year-old humans, but their descent from the top began with a 2007 study that ranked orangutans as smartest of the animals. Dolphins are beginning to get their due from researchers. A 2010 study placed dolphins as the second-most intelligent animal, second only to humans. Dolphins can recognize themselves in a mirror and inspect various parts of their bodies, and they can solve difficult problems while living in the wild and round up schools of fish with almost military-like precision. They’re so intelligent, in fact, that one researcher, Thomas White, an ethics professor at Loyola Marymount University in Los Angeles, says they deserve the same moral standing as humans. “The scientific research… suggests that dolphins are ‘non-human persons’ who qualify for moral standing as individuals,” he said.
Does this seem like a contest? Bees are smarter all the way, right? Not so fast, say some researchers. Although the queen bee has a pretty sweet deal—the rest of the bee colony serves her and she often lives up to three years—bees are smartest when they’re working together, as ants do. Both bees and ants have a complex brain, and they operate with “swarm intelligence,” meaning they are only smart when working in a group. Deborah Gordon, a biologist at Stanford University, told National Geographic that ants are “inept” individually, but ant colonies themselves can solve complex problems. The same is true for bees, although ants could possibly be even smarter, since there is no “queen ant” at the ant colony that the ants blindly serve. But what makes both ants and bees similar in intelligence is their shared instinct to work together toward a common goal.
Australia doesn’t have any real winners in terms of its bush animals, according to some biologists. Among the dumbest? The always adorable kangaroos and koala bears. According to Queensland biologist Dr. Rhonda Green, kangaroos are so challenged that they break the generally accepted wisdom that animals with longer infancy are more intelligent. But kangaroos still rank higher than koalas, which Dr. Green places as “very low” on the intelligence scale. A local children’s song by Harry Secombe teaches children early not to expect much from koalas: “Kenny is a Koala bear / He doesn’t walk he weaves / For his diet’s alcoholic / Eucalyptus leaves.”
Dogs recently came out above cats, but they may have to fight off pigs to top the ranks of domestic animals, some researchers say. While dogs are smart, researchers at Penn State University emphasize that dogs are very good at learned behavior—but not so much at figuring things out for themselves. According to researcher Brenda Coe, “a dog may learn Task A quicker than a pig, but a pig may learn Task B faster than a dog.” In fact, pigs can learn tasks almost as fast as chimps, long considered at the top of the food chain. But before you decide to get a pet pig, researchers caution that pigs’ primary motivation is food, while dogs’ primary motivation is an eagerness to please, making dogs the easiest pet to deal with. Unless, of course, you’re George Clooney.
Benjamin Franklin called Thanksgiving’s main course an “animal of courage,” but a 1997 Oregon State University poll found turkeys to be the dumbest of all the animals. Still, plenty of people stick up for turkeys, with one OSU scientist insisting that the animal gets a bum rap. “It’s an example of how a misunderstood animal behavior becomes identified as proof that the animal is extremely lacking in intelligence,” said animal science professor Tom Savage. Think about that next Thanksgiving.
