Intelligence of primates impressing scientists
WASHINGTON — 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.
“It’s not a question of whether they think — it’s how they think,” says Duke University scientist Brian Hare. Now scientists wonder if 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. It’s 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.
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 much as 14 hours. In nearly every case, when the apes realized they were being moved, they took their tool with them so they could use it to get food the next day, remembering that even after sleeping. The goal and series of tasks didn’t leave the apes’ minds.
Call says this is similar to a person packing luggage a day before a trip: “For humans it’s such a central ability, it’s so important.”
For a few years, scientists have watched chimpanzees in zoos collect and store rocks as weapons for later use. In May, a 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 can’t see it and uses that to his advantage, displaying the ability to perceive another ape’s situation. That’s 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 orangutan’s are humbled. Zoo associate director Don Moore says: “I’ve got a Ph.D., for God’s sake, you would think I could out-think an orang and I can’t.”
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.