At the Ngamba Island Chimpanzee Sanctuary in Uganda, everyone knows that Natasha is the smartest of them all. Now a series of scientific tests have confirmed her intelligence.
Natasha is well known for the ways in which she amuses herself, like beckoning visitors to come toward her, and then spraying them with water, and throwing branches at an electric fence to see whether or not the power is so she can then escape to another part of the sanctuary.
To get her smarts on the record, the sanctuary invited two scientists, Esther Hermann and Josep Call of the Max Planck Institute in Germany, to devise a series of tests and write up the results in a formal study.
The chimpanzees come to Ngamba from the entertainment business or have been kept as pets before growing up and becoming too strong to be handled. They are too habituated to humans to be returned to the wild. So a sanctuary is the best way of giving them a good life after they’ve been rescued. Ngamba is an ideal situation for them. It’s 100 acres of forest, grassland and sanctuary facilities on an island in Lake Victoria. Visitors are welcome, and they help support the sanctuary by staying at the tented camp and volunteering at feeding times all through the day.
The tests that Herrmann and Call set up included finding a hidden stash of food and using tools to complete specific tasks.
In the first test, designed to establish their spatial awareness, the chimps were invited to find hidden food. Another test required the chimps to use a tool and avoid a trap to get a food reward. Other tests demonstrated understanding of things like color, size and shape.
Natasha aced every test.
The researchers weren’t simply trying to see whether some chimpanzees are brighter than others, or who was the brightest, but to see if they could develop a standardized kind of IQ test for chimpanzees. According to Science magazine:
Herrmann and her colleagues had previously tested chimps in a study designed to compare the skills of the animals with those of human children. During the study, they noticed a wide range of skills among the chimps and wondered whether they could measure this variation in ability—and whether there were studies that could predict the chimps’ overall performance in all areas, like an IQ test in humans.
So they gave a battery of physical and social tests to 106 chimps at Ngamba Island and the Tchimpounga chimpanzee sanctuary in the Republic of the Congo, and to 23 captive chimpanzees and bonobos in Germany. In one experiment, chimps were asked to find food in a container after it had been shuffled around with empty containers. In another, they had to use a stick to get food placed on a high platform. The researchers analyzed the data to determine if the scores in some tests helped predict performance in others.
“In general, we don’t find any kind of general intelligence factor that can predict intelligence in all areas,” Herrmann says. “But we did find a big variation overall, and this one outstanding individual.”
Not surprisingly, the researchers discovered that chimpanzees who stood out in one area – say tool use – were not then automatically particularly good in another area. Just like humans.
“This study is top-notch and shows clearly that our traditional ideas about intelligence no longer hold,” Brian Hare [of Duke University commented]. “There are many different types of intelligence that vary independently of one another. This means there are many different types of genius, even in animals.”
The study is published in the Philosophical Transactions of the Royal Society B. In the abstract, the authors write:
We identified some individuals who consistently scored well across multiple tasks, and even one individual [Natasha] who could be classified as exceptional when compared with her conspecifics. However, we found no general intelligence factor. Instead, we detected some clusters of certain abilities, including inferences, learning and perhaps a tool-use and quantities cluster. Thus, apes in general and chimpanzees in particular present a pattern characterized by the existence of some smart animals but no evidence of a general intelligence factor. This conclusion contrasts with previous studies that have found evidence of a g factor in primates.
Here’s a video of the chimps doing their thing at the Ngamba Island Chimpanzee Sanctuary:
And the sanctuary’s website is here.