The more we study animals, the less special we seem.
Baboons can distinguish between written words and gibberish. Monkeys seem to be able to do multiplication. Apes can delay instant gratification longer than a human child can. They plan ahead. They make war and peace. They show empathy. They share.
Its not a question of whether they think; its how they think, Duke University scientist Brian Hare says.
Now scientists wonder whether apes are capable of thinking about what other apes are thinking.
The evidence that animals are more intelligent and more social than we thought seems to grow each year, especially when it comes to primates. Its an increasingly hot scientific field with the number of ape and monkey cognition studies doubling in recent years, often with better technology and neuroscience paving the way to unusual discoveries. This month scientists mapping the DNA of the bonobo ape found that, like the chimp, bonobos are only 1.3 percent different from humans.
And, says Josep Call, director of the primate research center at the Max Planck Institute in Germany, Every year we discover things that we thought they could not do.
Call says one of his recent more surprising studies showed that apes can set goals and follow through with them.
Orangutans and bonobos in a zoo were offered eight possible tools two of which would help them get at some food. At times when they chose the proper tool, researchers moved the apes to a different area before they could get the food, and then kept them waiting as long as 14 hours. In nearly every case, when the apes realized they were being moved, they took their tools with them so they could use them to get food the next day, remembering that even after sleeping. The goal and series of tasks didnt leave the apes minds.
Call says this is similar to a person packing luggage a day before a trip: For humans its such a central ability, its so important.
For a few years, scientists have watched chimpanzees in zoos collect and store rocks as weapons for later use. In May, a new study found they even add deception to the mix. They created haystacks to conceal their stash of stones from opponents, just like nations do with bombs.
Hare points to studies where competing chimpanzees enter an arena where one bit of food is hidden from view for only one chimp. The chimp that can see the hidden food quickly learns that his foe cant see it and uses that to his advantage, displaying the ability to perceive another apes situation. Thats a trait humans develop as toddlers, but something we thought other animals never got, Hare said.
And then there is the amazing monkey memory.
At the National Zoo in Washington, humans who try to match their recall skills with an orangutans are humbled. Zoo Associate Director Don Moore says, Ive got a Ph.D., for Gods sake, you would think I could out-think an orang, and I cant.
In French research, at least two baboons kept memorizing so many pictures several thousand that after three years researchers ran out of time before the baboons reached their limit. Researcher Joel Fagot at the French National Center for Scientific Research figured they could memorize at least 10,000 and probably more.
And a chimp in Japan named Ayumu who sees strings of numbers flash on a screen for a split-second regularly beats humans at accurately duplicating the lineup. Hes a YouTube sensation, along with orangutans in a Miami zoo that use iPads.
More than primates
Its not just primates that demonstrate surprising abilities.
Dolphins, whose brains are 25 percent heavier than humans, recognize themselves in a mirror. So do elephants. A study in June found that black bears can do primitive counting, something even pigeons have done, by putting two dots before five, or 10 before 20 in one experiment.
The trend in research is to identify some new thinking skill that chimps can do, revealing that certain abilities are not uniquely human, said Frans de Waal, a primatologist at Emory University. Then the scientists find that same ability in other primates further removed from humans genetically. Then they see it in dogs and elephants.
At Duke, professor Elizabeth Brannon shows videos of monkeys that appear to be doing a fuzzy representation of multiplication by following the number of dots that go into a box on a computer screen and choosing the right answer to come out of the box. This is after theyve already done addition and subtraction.
This past spring in France, researchers showed that six baboons could distinguish between fake and real four-letter words BRRU vs. KITE, for example. And they chose to do these computer-based exercises of their own free will, either for fun or for a snack.
It was once thought that the control of emotions and the ability to empathize and socialize separated us from our primate cousins. But chimps console, and fight, each other. They also try to soothe an upset companion, grooming and putting their arms around him.
I see plenty of empathy in my chimpanzees, de Waal said.
But studies have shown they also go to war against neighboring colonies, killing the males and taking the females. Thats something that also is very human and led people to believe that war-making must go back in our lineage 6 million years, de Waal said.
When scientists look at our other closest relative, the bonobo, they see a difference: Bonobos dont kill. Hare says his experiments show bonobos give food to newcomer bonobos, even when they could choose to keep all the food themselves.
One reason scientists are learning more about animal intellect is computers, including touch screens. In some cases, scientists are setting up banks of computers available to primates 24-7.
Limits to learning
There are limits to what nonhuman primates can do. Animals dont have the ability to communicate with the complexity of human language. In the French study, the baboons can recognize that the letters KITE make a word because, through trial and error, they learn which letters tend to go together in what order. But the baboons dont have a clue what KITE means. Its that gap thats key.
And that leads to another difference, said Steve Ross, animal cognition researcher at Chicagos Lincoln Park Zoo: Because apes lack language skills, they learn by watching and mimicking. Humans teach with language and explanation, which is faster and better.
Some of the shifts in scientific understanding of animals are leading to ethical debates.
When Emory University researcher Lori Marino in 2001 co-wrote a groundbreaking study on dolphins recognizing themselves in mirrors, proving they have a sense of self similar to that of humans, she had a revelation.
The more you learn about them, the more you realize that they do have the capacity and characteristics that we think of as a person, Marino said. I think its impossible to ignore the ethical implications of these kinds of findings.