Irene Pepperberg is associate research professor at Brandeis University and the author of a new book, Alex and Me. She and Jonah Lehrer, the editor of Mind Matters, discuss what Alex and other African Grey Parrots can teach us about the evolution of intelligence and the concept of zero.

LEHRER: What first got you interesting in study avian intelligence? After all, to say someone has a "bird brain" is insulting.

PEPPERBERG: I had parakeets as pets as a child, and I knew they were quite smart. For instance, they could learn to say words and phrases in context. But I didn't connect that to science at the time. I trained in chemistry at MIT and chemical physics at Harvard, not even knowing that a new field, animal cognition, was developing in psychology. It wasn't until I saw the first NOVA programs, in 1974, on ape signing, dolphin intelligence and the one on "Why Do Birds Sing?" that I realized that one could look at animal-human communication and animal intelligence in a scientific way. That’s when I realized that no one was looking at parrots, which could actually talk. I decided to use their ability to produce human speech sounds to examine their cognitive processes.

LEHRER: Were you surprised by Alex's talents?

PEPPERBERG: In general, no. But occasionally he would do something that was really impressive, jumping beyond the task at hand, transferring his knowledge unexpectedly from one domain to another. That’s when I’d get surprised.

LEHRER: What do you think was Alex's most impressive cognitive feat?
PEPPERBERG: The work on the “zero-like” concept. He had shown that he could label the number of a subset of items in a heterogeneous mixture (for example, tell us the number of blue blocks in a mixture of red and blue balls and red and blue blocks), but we hadn't tested his comprehension of number. That task was important, because young children, at a particular stage in number learning, can label a set but can't, for example, remove a specific number of marbles from a big heap.

So we were testing him on number comprehension, again showing him heterogeneous mixtures of different numbers of objects of different colors (for instance, two blue keys, five purple keys, six green keys and asking, "What color is six?"). As was his wont, he was at about 90 percent accuracy on the first dozen or so trials, but we needed far more for statistical significance. The problem was that he just did not want to comply. He began to turn his back to us, throw the objects on the floor, or give us all the wrong answers and repeat the wrong answers so that, statistically, we knew he was avoiding the correct response. We started bribing him with candies and treats to get him to work. One day, in the midst of this, I'm testing him with a tray of three, four and six blocks of different colors, and I ask, "What color three?" He replies, "Five." At first, I was puzzled: there was no set of five on the tray. We repeat this interaction several times, and he consistently says, "Five." Finally, in frustration, I ask, "OK, what color five?" He says "none"! Not only had he transferred the use of "none" from a same-different task, where "none" was the response if nothing about two objects was indeed "same" or "different," to the absence of a numerical set, but he had also figured out how to manipulate me into asking him the question he wanted to answer!

LEHRER: What can bird intelligence teach us about the evolution of human intelligence? Birds and primates parted ways a long time ago.

PEPPERBERG: Yes, primates and birds separated about 280 million years ago. But Alex's abilities show us that it’s important to examine parallel evolution and to be willing to examine how a brain functions, not only how it looks. The cortical-like area of the parrot brain looks nothing like human cortex, but it is derived from the same pallial areas as is human cortex, functions in a similar manner and takes up roughly the same proportion of space. We also must examine the conditions that likely selected for intelligence in evolution. Grey parrots, for example, like nonhuman primates, are long-lived and exist in a complex ecological and social environment. Likely the same conditions that selected for intelligence in nonhuman primates were at work in the parrot lineage.

LEHRER: In your book, you describe repeated examples of scientists and journals ignoring and discounting your results. Why do you think people are so resistant to the idea of bird intelligence? And have things improved?

PEPPERBERG: When I started my research, very few scientists studied any bird other than the pigeon, and used any technique other than operant conditioning. Pigeons did not perform very well compared to other animals (such as rats and nonhuman primates), and were thus considered to be lacking in intelligence; scientists extrapolated their findings to all birds. At the time, scientists didn't understand how the avian brain functioned, and thought it lacked any significant cortex. And, of course, when I began my research, some scientists started discounting much that had been done in the field of human-animal communication. So, when I started working with a parrot, and chose to use a nontraditional training method, few in the scientific community would give credit to Alex's achievements.

Whether or not things have improved depends a lot upon whom you ask. Many scientists do appreciate what Alex did and have been inspired to further investigate the abilities of all birds—not only parrots and corvids, but also to perform new research with pigeons. Other scientists, intent on proving the uniqueness of humans, tend to discount my research. Much of the work in avian cognition has shifted to Europe now, with large grants going to researchers in the U.K. (St. Andrews, Cambridge, Oxford) and other countries in the E.U. (such as Austria). Unfortunately, very little funding is available here in the U.S.


Are you a scientist? Have you recently read a peer-reviewed paper that you want to write about? Then contact Mind Matters editor Jonah Lehrer, the science writer behind the blog The Frontal Cortex and the book Proust Was a Neuroscientist.