Exploring the Avian Mind

by Caitlin Andrews

In June 1977, in a small laboratory at Purdue University, Irene Pepperberg stood with her arm outstretched toward a large bird cage, trying to coax a quivering Grey Parrot out of the cage and onto her hand. Just one year earlier, Pepperberg had received her doctorate in theoretical chemistry, having devoted years of her life to drawing up mathematical models of complex molecular structures and reactions, first as an undergraduate at MIT and then through her graduate work at Harvard (1, 2). Yet, here she was, completely spellbound by this trembling, sentient creature, whom she had named “Alex,” an acronym for the “Avian Learning Experiment,” of which he was to be the subject and star. “Here was the bird I hoped—and expected—would come to change the way people think about the minds of creatures other than ourselves,” Pepperberg writes in her memoir, Alex & Me: “Here was the bird that was going to change my life forever” (1).

From Chemistry to Cognition

To many, Irene Pepperberg’s decision to leave chemistry behind in pursuit of the new and largely uncharted field of animal cognition represented an unfathomable risk. But, looking back, Dr. Pepperberg knows that it was the right choice. “I was actually no longer intrigued by chemistry,” she says, “figuring that what was taking me years and years would soon be done in days via better computers” (2). In the late 70s, as she faced an uncertain job market, particularly for women in chemistry, she knew that she needed to find a new path. Although she had always loved animals, it was only when she began watching the NOVA television program on PBS that she realized that there were people using real science to study animals and to draw parallels between the animal and human minds.

Thinking back to her childhood in New York City, she remembered the pets with whom she had spent countless hours: a series of talking parakeets that had provided her with the type of companionship craved by a self-proclaimed shy and “nerdy” only child. As she watched TV programs about apes using sign language, dolphins exhibiting evidence of abstract thinking, and scientists unearthing the proximate mechanisms behind birdsong, Pepperberg realized that she had already encountered a subject that could provide just as much insight into the minds of animals (1). “I figured that a talking parrot would be an even better subject,” she says. “Birds and humans diverged about 280 million years ago, yet they have so many similar capacities, including vocal learning….I began reading, studying the field, and realized that, as [American zoologist] Donald Griffin said, communication was a window into the animal mind” (2).

The Alex Years

From the start, Pepperberg’s respect for animals and awareness of their needs, along with her technical background, proved to be a promising combination. She ensured that her studies would be representative of Grey parrots in general, as opposed to one particularly outstanding subject, by asking a pet store employee to select a random bird from the flock for her. When she finally coaxed Alex out of his cage at the lab, she kept careful journals of her interactions with him. And, right away, she got to work, using a two-person, interactive modeling technique to demonstrate the association between vocal words, or “labels,” and the objects that Alex encountered around the lab. In addition, each time she gave Alex one of these objects, she reinforced the label by repeating it and talking about its properties, while Alex watched and listened (1).

Over the first several weeks in the lab, Alex began to vocalize on his own, although, at first, his utterances were more “noise” than “speech.” But, gradually, Pepperberg was able to discern precise labels from Alex’s vocalizations; when shown a piece of paper, Alex would make a two-syllable sound, which Pepperberg would reward by giving him the piece of paper, until, eventually, he began to shape the sounds from ay-ah, to ay-er, to pay-er, and, finally, paper (1). Pepperberg and her assistants added more object labels—key, wood, wool—until Alex began to demonstrate an understanding that each label represented a category of objects that shared a certain property, such as shape or texture. For example, Alex could identify both a silver key and a red key as “keys,” transferring the label to a colored key that he had not encountered before. While this concept might seem simple to humans, Pepperberg knew that, for an animal like Alex, this was a significant accomplishment. As she writes in Alex & Me, “This kind of vocal cognitive ability had never before been demonstrated in nonhuman animals, not even in chimpanzees” (1).

Pepperberg often cites that interactive “model/rival” technique, which she used to train Alex, as a major reason for their success. Initially developed by German ethologist Dietmar Todt, the technique involves an animal subject and two trainers; while one trainer acts as the principal trainer and questioner, the other acts as a model for the desired behavior (e.g., labeling the object) and as a rival competing with the animal for the principal trainer’s attention. As Alex picked up more labels, adding colors and numbers to his already-extensive repertoire of object labels, it was crucial that he had humans to model proper pronunciation and label usage. Mostly, these were students who came to work in the lab. Pepperberg also found that it was important for Alex to learn that the same people did not always act as principal trainers or as models; sometimes she asked Alex questions, and sometimes she modeled correct (or incorrect) behavior and was rewarded (or not rewarded) by a student trainer (1). It was very important for the humans to make these occasional mistakes, and be scolded, so that Alex would observe the consequences of errors.

The work was not always easy. First, Dr. Pepperberg was dealing with a highly-intelligent animal who could pick and choose when he wanted to work—much more like a colleague than a research subject. Additionally, as she moved among various universities, she found that the fledgling field of animal cognition was not always met with the same enthusiasm that she had hoped was possible. But, the media picked up on Alex’s story and began to follow Pepperberg’s work (1). In his prime, with over 100 words in his vocabulary, “Alex made it clear to the scientific community that a ‘birdbrain’ could do the same things as an ape brain, and sometimes even those of a child’s brain,” Pepperberg says. “Alex and I were not the first to study avian cognition, but we had the widest impact, thanks to media coverage” (2).

Studying an animal who could communicate verbally set Pepperberg’s studies apart, because she could ask Alex questions and he could answer directly, giving insight into how he perceived the world around him. On the most basic level, he could identify an object’s material, color, and shape, and he could ask his trainers to take him somewhere (e.g. Wanna go back) or bring him something (e.g. Want banana). He also had a grasp for numbers; if shown a tray of assorted objects, Alex could answer questions about a particular subset of those objects (e.g. How many yellow wool?). He also showed evidence of being able to add small values, and, Pepperberg says, he could also “infer the cardinality of new number labels from their ordinal position on the number line—something no other nonhuman has yet accomplished” (1, 2). Alex understood concepts of “bigger” and “smaller,” as well as “same” and “different”—an important distinction, since it showed that Alex understood that several labels could be applied to a single object (1, 3). For example, given two square pieces of wood differing only in color, he could identify that the color was “different,” while the other properties were the “same”; if none of the properties differed among a pair of objects, he would indicate this by saying “none” (1).

Sometimes, Alex’s most impressive work came when it was least expected. One day, while testing number comprehension, Pepperberg presented Alex with a tray containing sets of different numbers of objects of various colors—2, 3, and 6 items. Because the sets were all different colors, she could ask Alex, “What color three?” But Alex, as he often did when he became bored with a particular study, insisted on avoiding the correct response. This time, he did so by answering “five,” even though there was no set of five objects on the tray. She repeated the question; he repeated his answer. Thinking that she could beat Alex at his own game, Pepperberg asked him, “What color five?” “None,” Alex replied, taking Pepperberg by surprise, as he transferred a concept that he had only ever used in reference to “same/different” or “bigger/smaller” to an entirely new context (1). “Western civilization didn’t have ‘zero’ until about 1600,” Pepperberg says. “And Alex transferred the ‘null’ concept himself” (2).

In her three decades of work with him, Dr. Pepperberg got to know Alex more deeply than most any researcher ever gets the chance to know her subject. Working with a single animal for such a long time is “fascinating,” she says, “because one gets to know so much about the individual—not just what is studied, but all the personality quirks and the temperament.” Some of these “quirks” were incorporated into published studies, such as how Alex spontaneously invented his own label for an apple—which he called a “banerry”—out of a combination of the labels “banana” and “cherry” (1); as Pepperberg says, this provided evidence that “Alex clearly did more than repeat what he learned vocally; he parsed his labels to make new ones, much as do humans” (2). But other examples of Alex’s quirks serve only as anecdotes to illustrate the unique individual that he was—like how he called cake “yummy bread” when he first tried it, or how he would say “You be good. I love you,” as Pepperberg left the lab each night.

These were his last words to Dr. Pepperberg, as their pioneering studies came to an abrupt halt in 2007 when Alex died suddenly at the age of 31. Although, at that point, Pepperberg’s research had involved several other parrots in addition to Alex, his death was devastating to her and many around the world. However, Pepperberg sees her work and the work of others in her field as emerging. She knows that there is a broad-ranging potential for animal cognition, in terms of its implications for animal welfare and conservation, as well as for the development of teaching methods for children with cognitive deficits. “When I started, the field barely existed; ‘animal cognition’ was almost considered an oxymoron,” she says. “Today we have journals that are specifically devoted to the field….Only by continuing to study a variety of species will we really understand the various capacities of different ‘minds’” (1, 2).

A Return to Harvard

In July 2013, Irene Pepperberg returned to the campus where, almost four decades earlier, she had received her doctorate in theoretical chemistry, not knowing the path that she would set out upon soon after graduating. While she had been a Research Associate in the Vision Lab at Harvard since 2005, and teaching classes in animal cognition and human-animal communication at the College and the Extension School, her research base had been at Brandeis for the past decade. But, after securing a lab space at Harvard, she moved to William James Hall in July, bringing with her Griffin—an 18 year old African Grey Parrot, who had lived and learned alongside Alex for much of his life.

Having had Griffin since he was only seven and a half weeks old, Dr. Pepperberg knows Griffin’s quirks just as she knew Alex’s. And, Griffin is certainly his own bird. He gets “self-conscious” when he struggles with a particular label and is more hesitant than Alex was—something Alex would sometimes take advantage of by prodding Griffin to produce the correct vocalization, while other times seemingly wanting to help by hinting at the  correct label (1). Although Griffin speaks less now that Alex is gone, he has a list of impressive accomplishments to call his own. Most recently, he showed that he had an understanding of the benefits of sharing, as he chose to share a reward rather than act selfishly so long as his partner was also willing to share (4). He has also done work with optical illusions, demonstrating an ability to recognize occluded objects, providing insight into the commonalities between how birds and humans perceive the same visual illusions (2).

But, Griffin has not been alone in the Harvard lab. In addition to a dozen human research assistants, he also gained a new companion in October. Hatched in April 2013, Athena is Dr. Pepperberg’s first female African Grey. “So far, working with Athena seems to be a cross between my early work with Alex and that with Griffin,” Pepperberg says. “We learned a lot from both of the previous birds and are implementing some of that with Athena” (2). Over Athena’s first six months in the lab, research assistants have been working with her constantly on vocal labels and even audio recording her progress, from her very first warbles to her recently more distinct-sounding “wood” and “key” labels. “What will be really interesting is that new computer techniques and analysis tools will let us track her vocal development in ways that I couldn’t manage with Alex or Griffin,” Pepperberg says (2).

While, at the moment, Griffin is still warming up to the idea of having a new “little sister” around, Pepperberg hopes that Griffin will act as a model for Athena as she begins to learn new vocal labels. With only two birds, she will not be able to draw any definite conclusions about sex differences in cognition. However, she may be able to say something about how cognitive abilities develop over the lifetime of an individual, comparing Athena’s abilities with Griffin’s, and also tracking Athena’s progress over time, much in the same way that she did with Alex.

As for her experiences at Harvard so far, Dr. Pepperberg enthusiastically says that “So far, it’s been terrific!” She sees many opportunities for collaboration between herself and other members of the Psychology Department, and she is excited by the possibilities for the future. As she writes in Alex & Me, “Alex left us as a magician might exit the stage: a blinding flash, a cloud of smoke, and the weaver of wizardry is gone, leaving us awestruck at what we’d seen, and wondering what other secrets remained hidden…wondering what else he would have done had he stayed” (1). As Dr. Pepperberg embarks on the next leg of her journey, it is clear that, while Alex is gone, perhaps these secrets may be revealed through a new set of voices.

Caitlin Andrews ‘16 is a sophomore in Eliot House concentrating in Organismic and Evolutionary Biology.


  1. I.M. Pepperberg, Alex & Me (HarperCollins, New York, 2008).
  2. I.M. Pepperberg, personal interview.
  3. I.M. Pepperberg, The Alex Studies (Harvard Univ Press, Cambridge, MA, 1999).
  4. F. Péron, L. Thornburg, B. Gross, S. Gray, I.M. Pepperberg, Human-Grey parrot (Psittacus erithacus) reciprocity: a follow-up study. Animal Cognition (2014).
Exploring the Avian Mind
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