WALTHAM, Mass. -- Griffin seems depressed. He's less talkative than usual and has lost some interest in learning. Given the death of his roommate, it might not take a psychologist to diagnose depression. Except Griffin, who lives in a psychology-department lab at Brandeis University, is an African gray parrot.
Griffin's trainer, scientist Irene Pepperberg, balks at applying the label "depression" to a bird. But she says she is not feeling so good herself.
"Where do we go from here?" she asks, referring to the loss of Alex, the rock star of the parrot world who dominated her lab and her life for 30 years. Alex died unexpectedly in September of a heart arrhythmia.
Alex could identify colors and objects, such as "rock," "wood" and "wool." He could identify "bigger" vs. "smaller" and knew a triangle as a "three-corner" and a square as a "four-corner." He could say how many objects were a particular color and shape ("how many green blocks?") as well saying "none" when a set of items was not present. When trainers worked with his labmates Griffin and Arthur, he sometimes interfered — answering for them, telling them to "say better" or posing a different question about the items.
Because parrots have the rare ability to mimic human speech, Pepperberg says, their spoken responses on intelligence tests can give researchers insight into how bird brains function. Other researchers worry, however, that the very use of human-language terms may cause researchers to infuse the birds' speech with too much human meaning.
A longtime collaborator, biologist Russell Balda of Northern Arizona University, calls Pepperberg's work groundbreaking. "She's shown the higher-level abilities of parrots to not only figure out complex relationships but also express them in human terms."
But after Alex's death, many investigators still don't know what to make of him. Was he an avian Einstein, or could many birds have the same abilities?
Alex's second language
Pepperberg started her career at Massachusetts Institute of Technology and moved on to Harvard University, where she earned a doctorate in theoretical chemistry in 1976. She owned budgies, a kind of parrot, as a child and had one in high school that seemed bright to her. After seeing TV shows about singing birds and chimps that used sign language, she decided to do intelligence research on parrots by teaching them human speech and then asking them questions. She got Alex the year after she earned her doctorate.
At the time, researchers were examining the cognitive abilities of birds, but having them respond with English labels was a novel approach. "When I put my first grant proposal in," Pepperberg says, "people practically asked me what I was smoking."
With Alex, Pepperberg used a second trainer to model correct responses and compete with the bird for the attention of the first trainer. In an effort to see whether this "model-rival" model was the best technique, she spent several years trying other methods on the younger parrots, with less success. She has returned to the model-rival method with them, but they haven't come as far as Alex yet.
At Harvard, where Pepperberg also teaches, students crowd into her small classroom. She raises her hand to make a point, and even in the low light, a crisscross of talon marks is visible on her skin.
For this class on animal cognition, she uses journal articles as a textbook, encouraging students to poke holes in the research. She asks them to examine skeptically what's being measured and to consider whether the results support the authors' conclusions.
Research doesn't fly with everyone
Some researchers take the same approach to Pepperberg's work.
University of Florida psychologist Clive Wynne hesitates to give credence to research that focuses so heavily on one investigator and one subject. He notes that Pepperberg has not had nearly the same success with other parrots, and neither has anyone else.
But zoologist Bernd Heinrich, author of Mind of the Raven, sees Pepperberg as the only one "with such a long-term relationship and a long-term interest in what the bird could understand." Pepperberg reports that the birds spend up to 10 hours a day with people.
Wynne says, however, that the big question remains how similar human and animal thinking really are. "I personally think that arguments for the similarities have been pushed too far," he says.
The University of Kentucky's Thomas Zentall says scientists may not have seen some kinds of intelligence in animals because they haven't been looking. His work has shown that pigeons, like humans, value rewards more if they have to work hard for them.
Heinrich says his studies of ravens indicate that they can anticipate what another raven will do and make plans to counteract that behavior. He concedes that birds "are not going to do nuclear physics. But we've found more complexity than we expected, with unanticipated, amazing results."
In the lab, Griffin nestles closer to Pepperberg. Later, he will sit on his perch and answer questions about rock and wool. For now, he roosts on her hand like any pet bird, then ducks his head and nips her.