New research shows that we have grossly underestimated both the scope and the scale of animal intelligence. Primatologist Frans de Waal on memory-champ chimps, tool-using elephants and rats capable of empathy.
A herd of African elephants drink water at a dam inside the Addo Elephant National Park near Port Elizabeth, South Africa.
Who is smarter: a person or an ape? Well, it depends on the task. Consider Ayumu, a young male chimpanzee at Kyoto University who, in a 2007 study, put human memory to shame. Trained on a touch screen, Ayumu could recall a random series of nine numbers, from 1 to 9, and tap them in the right order, even though the numbers had been displayed for just a fraction of a second and then replaced with white squares.
I tried the task myself and could not keep track of more than five numbers—and I was given much more time than the brainy ape. In the study, Ayumu outperformed a group of university students by a wide margin. The next year, he took on the British memory champion Ben Pridmore and emerged the "chimpion."