Alex, the African gray parrot, died young. For three decades he redefined our understanding of animal intelligence with his humanlike ability to count, describe objects and express his desires—but he was expected to live another 20 years when an undetected arterial disease took his life. Still, the legacy Alex leaves is remarkable. According to all but the most stubborn critics, he demonstrated skills far beyond mere mimicry, suggesting that he was, in fact, a thinking being who truly understood the meaning of his words. He could apply newly learned concepts to novel situations and often used his limited vocabulary in inventive ways. For instance, when presented with an apple for the first time, he reportedly called it a “banerry,” a portmanteau of the familiar labels “banana” and “cherry.”

To teach Alex to talk, psychologist Irene Pepperberg of Brandeis University refined the “model-rival” technique, in which a third party demonstrates the correct response and competes for the teacher’s attention. Sometimes this third party was another scientist in Pepperberg’s lab; sometimes it was Alex, helping to train a younger bird. This role reversal is such a powerful learning tool that clinicians are now successfully using the technique with autistic children—extending Alex’s scientific contribution far beyond the study of bird brains.