Kim Mills: With phrases like "what a bird brain" or "that's for the birds," the English language doesn't offer much respect to avian species. But for decades, researchers have known that some birds are more intelligent than they're usually given credit for. From parrots that can communicate with words to crows that use tools, psychologists and other researchers have found that birds can be as smart as primates or even in some cases human children.

Today we're going to talk to one of the world's leading experts on bird cognition and communication about how birds think, the extent of their intelligence, what they can do that might surprise you and what they can teach us about intelligence in general.

Welcome to Speaking of Psychology, the flagship podcast of the American Psychological Association that examines the links between psychological science and everyday life. I'm Kim Mills.

My guest today is Dr. Irene Pepperberg, an adjunct research professor at Boston University in Boston, Massachusetts. She's spent nearly 5 decades working with gray parrots, training them to communicate in English and studying their intelligence. Her research has found that gray parrots are in some areas as intelligent as 5- or 6-year-old children. Her most famous work was with a parrot named Alex, who died in 2007. Today she runs the Alex Foundation, which supports her continuing research. She's also held many academic appointments, including at Harvard University, Brandeis University and MIT's Media Lab. She's authored more than 100 academic publications and two books, including the memoir Alex and Me. Her life and work were recently the subject of a play called Beyond Words, performed in Boston last spring.

Mills: One detail I didn't mention from your biography is that your PhD is actually in chemical physics, not in psychology or animal behavior. So why don't you start by telling us about how your career with the birds started. What sparked your interest and how did you decide to make this big switch?

Pepperberg: It started actually when I was a young child. I lived above a store in Brooklyn. My father was working full-time, going to school and taking care of a sick mother, so I barely saw him. My mother would've been great in my generation. She wanted a career, but in those days, you had a child, you were fired and you had to stay home. So she took care of my physical, but not my emotional needs. And my father bought me a little parakeet, a little green budgerigar that you would get at what the stores then were, Woolworth's, and that bird was my constant companion, and I think I must've imprinted on this with this little budgie.

So fast forward, I was very good in chemistry. I was getting my doctorate in Harvard and I was rather disillusioned at that point. It was unfortunately a very sexist atmosphere. We were told that there was no way we'd ever get a job at a place like Harvard because they would never hire a woman because we weren't good enough. And we sat there saying, but you're giving us PhDs. Don't you think that's good enough? And the answer was no. I also realized, and this was even more important, I was doing a mathematical modeling of reaction rates and chemical structures, and it was taking me 7 years. And I realized that the way computers were going that a while, it wouldn't take someone 7 years, but it would take them 7 minutes. Of course now it's 7 nanoseconds actually. And I just didn't see any future in this.

And at the same time, my then husband and I had been living in an apartment in Cambridge that was set on fire by an arsonist. We ended up moving into his postdoctoral advisor's house because his advisor had just gotten a divorce and had two young children. He needed help with the kids. We needed a place to live. So we became kind of au pairs and we used to babysit for the children, not very often, but just enough. And we would always try to do things like educational TV, such as NOVA programs. And this is leading somewhere because the NOVA programs at that point were on things like, why do birds sing? And the signing chimps and the computer-using chimps and the dolphin language work. And I was thinking to myself, I love animals. I had a budgie that talked, why aren't they using parrots for this type of work?

So I went over to the Museum of Comparative Zoology. I said to them that I wanted to switch fields. They said, No, no, no, you're ABD, just finish the doctorate. It's a union card. But you can sit in on any of my courses. We don't care. So they said, Just don't make us grade your papers. And I said, Fine. And I cut the same deal with the psychology department. And so I was going to all these incredible seminars on animal behavior and child language acquisition, which was also in its infancy. At that point, people were just beginning to figure out how children learn to speak. So there was this plethora of just amazing research that I could immerse myself in. So I spent 40 hours a week finishing the doctorate and 40 hours a week doing all this other stuff, and that's how I started the switching fields.

Mills: Can you tell our listeners more about what it means when people say parrots are as intelligent as a 5- or a 6-year-old child? In what ways are they smart? What kinds of things that can they do that might surprise people?

Pepperberg: Well, there are a bunch of studies that have been done with children, particularly ones by the Swiss psychologist Piaget. People may have heard of him. He studied child development and child psychology, and he came up with a list of types of tasks that you would give children at different stages in their development. And we've given the same types of tasks to our birds. So one such task, it's -- everybody probably knows the test. They probably haven't known that it was Piaget. But you take two glasses of water, they're half full glasses of juice actually, they're half full. And you give it to the child and you say, which one do you want? And they giggle -- whatever age they are, they giggle -- and they say, It doesn't matter. Then you pour one into a tall thin glass and one into a short fat glass, and then you give it to the child and say, Which one do you want?

If the child is under about 5 years old, they'll generally point to the tall thin one and say, That one. And you say, Why? And they say, Because there's more. And you say, But you just tell me it was the same. Well, now there's more. Okay. No conservation of material. If you ask a 6-year-old child, they may point to the same glass, but then you ask them why and they'll say, Oh, because it looks like it's more fun to drink out of. They know it's the same amount of liquid, but you ask them to choose and they come up with a reasonable explanation.

Well, we gave this type of task to our birds and they passed. We gave them another Piagetian task on probability. So this is again another fun one, very simple. You have a bucket, you put three blue marbles in and one red marble in, and you mix it up, it's an opaque bucket. And then you take out one marble. The child doesn't know which marble it is in your hand, and you ask the child, What do you think? What color do you think it is? And if the child is, again, 4 years old or so, they'll say, Oh, because red's my favorite color. So it's red. Or they'll say, Well, you put one red one in and you took one thing out, so it has to be red. There's some logic, but it's not the right one. You ask a 6-year-old child and they'll say Blue. And you say, Why? Well, you put more blue in, so it's more likely to be blue. And we gave that type of test to my parrots, and again, they passed.

Pepperberg: Exactly. Or we actually, with our birds, we asked how different t objects -- so it was pieces of paper and keys or pieces of wood and corks, and we mixed all the different combinations so they couldn't say the same thing all the time. Because we had one bird, so we had to ask him 96 times. Piaget asked the children once or twice.

But yes, he, we'd say, what do you think is in here? And he couldn't possibly know, but he'd have to make an assumption as to what it was. And he picked the larger number, the larger amount, 75% of the time and the smaller one 25% of the time. So he tracked the probabilities.

Mills: Now how did you end up with Alex? And why go with a gray parrot among all the birds that are available in the world?

Pepperberg: It's easier to answer your second question. The reason I chose a gray parrot is first of all, they are the clearest talkers of all of the parrots. They have a slightly different muscular system that allows them to talk more clearly. And second, there had been work in Germany by a professor Otto Koehler on number concepts in gray parrots. So he already had shown that these birds were quite smart. They can actually identify sets of numbers up to about six or eight, I can't remember which one he was working on, but six or eight. So there was some evidence that I could write when I was putting in a grant proposal to say, Hey, these are smart birds.

Alex was a random choice. We had gone to a lot of different pet stores. We finally found one that had birds that had been raised in the states. We didn't want a wild caught bird for a lot of reasons. I mean, it's just a horrible thing to decimate the wild population. And there were a cage of eight birds and I asked the fellow to pick one out just randomly. I didn't know anything and I didn't want anybody to think that I chose a special bird. So he just took a butterfly net scooped one up, got it out, flipped it on it back, clipped its wings, says it speaks it, here.

Mills: Now you taught Alex more than 150 English labels to describe objects, colors, numbers, and other things, but you always use the word labels rather than language when you talk about communicating with parrots. Why is that?

Pepperberg: Well, language is very special. I know I have a lot of colleagues who talk about ape language or whale language and things like that. We don't yet understand the complexities of their communication system. We do know a lot about ours, and ours is so much more complex than we have ever been able to teach a non-human. So you and I can talk about anything. We can talk about things that don't exist. We can talk about the future. We can talk about the past. No matter how long we will have trained any of these animals, they are not using our speech patterns or our signs. If they're using sign language or our plastic chips or computer symbols, they're not using them in those types of complex ways.

It's definitely interspecies communication. I mean, we are communicating with them -- just not at the same level. So I'm very careful to make that distinction. The animals have their own separate communication system, which might be much more complex than we understand. We are actually asking them to learn a second language. Now think about that. We have been too stupid to learn their codes, but we're asking them to learn our code. So I'll leave it at that.

Mills: Now you've also done some experiments that look at how well parrots do on the famous marshmallow test, which looks at how well a child, or in this case a bird can wait for reward. How do parrots compare with children on that test?

Pepperberg: They are almost identical. Not only could our bird Griffin wait for 15 minutes for a better reward or more reward, but to distract himself during the waiting period, he engaged in the same types of behaviors that the children did. He would sing to himself, he would turn around and preen, he would fall asleep. I mean, we actually have a little video split screen video of some children whose videos we've taken off YouTube and the same behavior in our bird while he's waiting.

Mills: And you've looked at bird's mathematical abilities, which includes their ability to recognize numbers and grasp the concept of zero. Can you talk about that? How does a bird understand zero?

Pepperberg: Well, I called it a zerolike concept because it wasn't exactly zero. He died before we could teach him enough to see if it really was zero. But what happened was we had trained him to identify sets of objects, so he could look at a set of mixed objects, blue and red balls and blocks all mixed in. And I could say, what number blue block? And he could tell me up to six at that point. We then did comprehension studies where we'd put mixes of different colors sets and say, what color is six? So we'd have to find the six and the set and tell us the color. We also later trained him. So he understood up to eight as an exact number.

But when we were doing the comprehension study, he was completely bored. He had been doing numbers for so long at this point and we had to ask him like 60 trials to get statistical significance. So he did the first 12 trials absolutely perfectly. And then we start giving him the second and he looks at the things on the tray and he takes his beak and he knocks them all off, or he turns around and he starts preening. Or the worst case scenario is he'd look at the blocks and if they were like yellow, green, and blue, I say, what color six? And he tell me, orange, purple, all the colors that were not on the tray. So this was getting rather frustrating. We switched to using things like jelly beans, which he really liked. And he could have a jelly bean if he was correct. It was still really tough going.

And then one day I walk in with sets and I have three, four, and six things on the tray. And I say, Alex, what color three? And he looks at me and he goes, five. And I go, what color three. There's no five things the tray. So what color three? Five. We go back and forth a couple of times. So he's not throwing things on the floor. He's not giving me all the wrong colors. He's not ignoring me. So I look at him just, I mean, alright, smarty, what color five? thinking, whatever. And he looks at me and he goes, none.

Now he had learned none in response to the absence of attributes on the task of same and different. So we could show him two things and ask what's same and what's different. And he'd say, color, shape matter or none if nothing were same or different. So here he transferred the concept of the absence of an attribute to the absence of a set, and we were able to test that out and that was solid. But if we gave him nothing on the tray and said, what's there? He didn't say none. He didn't quite make the transfer because we had never trained him to use that to mean total absence of everything. So that's where we were when he passed away.

Mills: Now I know you've done your work with parrots, but are other birds as smart as parrots or are they just intelligent in different ways?

Pepperberg: Most of them have been tested in different ways. So you have the tool-using cockatoos, which are incredibly amazing. You can give them a box that needs six different, I think five or six different types of latches and screws and things to manipulate to open the box and they'll figure out how to do it. You've got the tool making crows. You've got a lot of different work with these different birds. So there was crows that would do the Aesop's fable task where it would learn to drop stones into a dish of water until the water was high enough so it could take the seed off the top of the water. So they've all been tested on different types of tasks and it would be really interesting at some point for us to get together and do similar types of tasks. But grays are really bad at tool use. Their attitude is, Hey, I've got a Swiss army knife on the front of my beak and that's all I need. That's good enough.

Mills: That's good enough. Yeah. Is there a connection between bird song and the speech of parrots and do birds learn to sing the same way that parrots learn words?

Pepperberg: Oh, that is a good question. We don't know for sure, but we do know that the brain structures are very similar in songbirds and in parrots and in humans. In fact, there are seven structures in all of those brains that seem to be responsible for vocal learning. So they're arranged in slightly different ways and they're connected pretty much the same way though. What is interesting is the parrots, like Alex, have another shell it's called. And that is the thickness of that area seems to be related to the ease at which these birds learn their non-special specific vocalizations, their ability to say mimic speech. So a Kea, which is a very smart parrot, that's another one of these tool using parrots that's really, really smart, has a very thin shell. And it's not known for mimicking human speech. Grays have a very thick shell and they're one of the best mimics of human speech. But we do know that those brain structures are pretty much similar across those species.

Mills: Once in a while other bird species will learn some words. Is that because they have some physiological difference? I mean, I think you talked about your budgie knowing some words, which is also a parrot, but I think that there have been what -- starlings that could do a little talking.

Pepperberg: Yes. And again, it's this song learning mechanism, the seven areas in the brain that are responsible for the speech learning. And we would assume that birds like starlings may or may not, they haven't been studied yet, may have some of this additional shell area that allows for the heterospecific vocalization.

Mills: One really fascinating aspect of your work is the relationship that you develop with birds over time. I've heard you describe them as colleagues. Why do you use that term? Tell us more about the relationship that you have with the birds you study.

Pepperberg: Yeah, people ask me, well, are they your pets? And the answer is no. Are they your subjects? And I have to say that they are much more than subjects because all the work that we do is dependent upon their being willing to work with us. We don't limit their food intake, we don't limit their water intake. We do limit their treat intake. But that's kind of makes more sense. You wouldn't give children cookies all day. So the fact is if they want something that's the parrot equivalent of a cookie, yes, they have to work with us, but hey, cookies are optional.

The idea is that we try to do things that would intrigue them, would interest them, would get them to want to work with us. And again, you care for your colleagues. People ask me about my emotional bond to the birds and I have to have a certain amount of distancing to be able to look at all the work dispassionately and to be able to evaluate it dispassionately. But that doesn't mean I don't care for them. The way you care for a colleague, I mean, you like your colleagues, you ask how their weekends were and things like that, but you don't cross a certain line with the way you feel about your colleagues. And that's what we had to keep careful with our birds, so we could care for them. We could have some kind of emotional bond with them, but we had to draw a line as to how far that could go.

Mills: So you're working with two other grays right now, is that correct? Can you tell us about those birds?

Pepperberg: Yeah, there's Griffin, who's 29 years old. And Athena. We worked with the Piagetian studies with them, with the liquid conservation studies with them. We did the probability study and the marshmallow study with Griffin. We've been doing some more work with Griffin on visual working memory and another work on something called inference by exclusion, which means figuring out where something is by being given information about where it's not. So those are a lot of the studies. We've done a lot of work on optical illusions first with Alex, but now also with Griffin. And they seem to see them the same way we do, although the most recent one we're working on, that may not be the case, but we're just beginning to collect data on that, so we really don't know where that's going to lead.

Mills: Do you see a difference in the intelligence among these three birds in particular or personality, I mean if you even feel that they have personality?

Pepperberg: Oh, definitely a personality. Alex was incredibly smart and also basically was very eager to learn and eager to test things and see what happens. So it was like with none, he just would want to push things. Griffin grew up with Alex being his critical older brother. So I mean when they're first learning their labels, the labels aren't clear. They won't go and just say green, but they'll go "gee" and you have to work with them to make it clear. So we'd be asking things like Griffin, what color? And he'd go green. And Alex would say, no talk clearly, say better. Or we'd ask Griffin, Hey, what color? And Alex would say, no, tell me what shape. And Griffin would look at him, look at me, shrug his little birdie shoulders and go do I answer him, do I answer her?

So Griffin is turned out to be also really, really smart. But the student who says, tell me what I have to do to get the A, just show me what I have to do to get the, and I'll do it and I'll do it in spades, but I'm not going to try something new because I could make a mistake and I'm going to get yelled at. So, and Athena, she can speak very clearly when she wants to, but her attitude, her very different personality, it's like, I said orange, why do I have to say it again? I can say it. I know that you know that I, that I can say it. So we're done. And it's of course very frustrating to get statistically significant data from her because of that behavior.

Mills: Now that is a criticism that I have heard. How could this be statistically significant? Because you're really only working with a very small number of birds. What is your answer when other researchers say that to you?

Pepperberg: Well, I mean there's basically the idea that if one individual can do this task, and if you document that individual's work very, very carefully, which we have done, then it suggests that the species is capable. It doesn't mean that every member of the species will do it. I mean like Athena, I'm not sure how much data we're going to get from her, but for Griffin and Alex, you see that it's like looking at humans. We say that humans, humans are brilliant. We have Einstein, we have Beethoven, we have Picasso, we have all these incredible things that humans have done, but not every human can even solve an algebra question, can sing any kind of a tune, can hold a paintbrush straight. But we look at those individuals and say, well, they could do it so humans are capable.

And so that's what I'm trying to tell people. I mean, if Athena had been my first subject, we might not be talking today. And that's not to say that she isn't smart, but she's just not -- her personality is such that she just doesn't care that much about showing us that level of smartness. Whereas Alex and Griffin really did, and it's not a male female thing because I sometimes work with two other grays. They belong to colleagues who worked in my lab for a while, and they have their own grays. They now live on the Cape. And we sometimes use their birds. They worked in the lab, they understand experimental design and they understand they have to send me every videotape of their bird. Even if their bird is acting stupid, they know they have to send it and they don't have to follow the protocol exactly. And their bird Pepper has done a lot of the same things that Griffin has done, as has the other bird Franco. So it's not a male-female thing, it's a personality thing.

Mills: What does research on bird intelligence tell us about intelligence more broadly, whether that's with other animals or with humans?

Pepperberg: Well, it does talk about the evolution of intelligence. When you think about the fact that humans and birds have been separated by over 300 million years of evolution, go back to the dinosaurs essentially. So we've had this convergent evolution and we can show that these totally different species have similarities in common, and that makes us think about how many other species might be intelligent and do this kind of work if they were studied appropriately. It also suggests that we should realize that not every brain has to look humanlike, or even primatelike. If you look, I talked about these seven centers of vocal learning in the bird brain, but if you just look at a bird brain, it just looked like a blob of Jello. If you compare it to our brain that has all the, they're called gyri and sulci, but all the ups and downs and curves and stuff, you know what I'm talking about. When you look at the picture of a brain, a bird brain just looked like a blob of Jello. But there are areas in that brain that correspond to the same areas in our brain. They're cortical areas that they don't look cortical, but they act like our cortex and the same with other different areas. So it suggests that we should look far and wide for the types of intelligence that are out there.

Mills: When you first started doing this work in the 1970s, you were one of a handful of people who were doing this kind of research. How has the field developed over the ensuing decades?

Pepperberg: By leaps and bounds. I mean, my first grant proposal came back literally asking me what I was smoking. I mean, this was the '70s. And a little aside from that, I met the person many years later who had written that and he apologized. But the point was that people really didn't believe it, because I mean, there was no neurobiology. It wasn't until 2005 that people really recognized the similarities between the avian and the primate brain. But there are so many groups now who are looking at avian intelligence across the world, and it's really exciting to see how this has changed. We now have a society called comparative cognition, but it's only 30 years old. There was 20 years there where we were still trying to make our way in the field and get people to treat us seriously.

Mills: So do you feel vindicated as a researcher or are there still a lot of skeptical scientists out there?

Pepperberg: A combination of both. I mean, there are still some people who sort of go, well, yeah, maybe there are a couple of birds that are smart, but and then the majority of people do seem to appreciate that we need to look at all the creatures with whom we share this universe and start appreciating what they might be able to do. And again, we have to realize that what I do by comparing them to young children is to make it clear to humans how smart they are, because humans only understand that kind of comparison. But if you think about the kinds of things that animals do in the wild and survive in the wild and all the techniques they use and all the different abilities they have, I mean, a lot of animals here notes that we can't possibly hear either high or low. Okay. Elephants have what we call infrasound, dolphins use ultrasound.

Okay, vision, birds seeing the ultraviolet. They see so many more different colors than we do that we can't even imagine what it's like. You think about animals that have sensing small degrees of temperature sensing, and that's how they get their prey, that track one another. Just think about how well your dog senses things. And we are totally incapable of doing that type of thing. So we need to appreciate these animals, not just because they can do humanlike tasks and what's the technical term is their Umwalt, their environment, their everything that surrounds them and their way they see the world and not just see the world, but the way they sense the world in all different ways.

Mills: In the interest of full disclosure, I have to out myself as someone who had pet cockatiels for many decades. My last one died a couple of years ago at the age of, I think he was about 35. And he even made a few appearances on this podcast because he was noisy. But given how smart parrots are, how do you feel about people keeping them as pets? Is it fair to the parrot?

Pepperberg: Well, that's again, another really good question, and I answer this by asking the people who want to keep parrots, what's their lifestyle? So somebody comes up to me after I give a talk and says, I want a parrot just like Alex. And I say, well, what do you do? Oh, I have three kids and I take them to all their different activities and I work 18 hours a day and have a two hour commute. And before they say anything else, I say, get a picture of a parrot and put it on your refrigerator. Okay? Because parrots are flock animals. A single bird in the wild is a dead bird. They can't eat and look for predators. At the same time they communicate with their flock members, they preen one another, they interact with one another. You can't do that. And then they say, we'll get two birds. And I say, and how close to you are you to your freshman college roommate who was chosen for you?

Then I get somebody who says, I work at home most of the time and I don't travel very much. And I say, that could work. It's not that you have to interact with the bird 24/7 or even 12 hours a day the way we do with our birds, but they like to have the companionship. They want to sit on the perch near you. It doesn't mean -- you probably experienced this. That doesn't mean you have to be scratching their head all the time or interacting with them all the time, but just the fact that they can see you, they feel safe because you're with them and things like that are really important to them.

They need cages. I mean, a cockatiel, it's easy because you don't need a huge cage. But think about most parrots, they need to be able to stretch their wings fully. They need to be able to glide a little bit. They need those kinds of experiences. You wouldn't take a 6-year-old child and put it in a playpen for 8 hours a day with a couple of snacks and some games and say, here, that's your life, which is what we do to some of these birds. So I tell people to really evaluate their lifestyle before and again, if they do decide to get a bird, make sure they get one that's been hand raised and if at all possible to have been at least weaned by the parents before being taken away because that's another issue that we're finding is really important.

Mills: So just to wrap up, what's next on your horizon? What are you working on? What are the big questions that you still want to answer?

Pepperberg: Well, one of the big ones is this visual working memory that I've talked about. Mentioned briefly. So it's basically a shell game on steroids. And what we do is you take the hardest of the tasks. You have four little colored pompoms, you put little black cups over all four of them, and then you start doing swaps. And after you've done four swaps, then you pick up one color and you say, find the yellow one. So you have to have tracked all four of them. Griffin beat out 6- to 8-year-old kids completely on this task. He beat out Harvard undergraduates until we got to the four cups and four pompoms. Then he cratered some, but he was so bored at that point that I'm not sure it was really fair. But he did. I mean, he was really good on, he beat out the Harvard undergraduates on four cups up to two swaps, and then on three swaps he fell down a little bit and in four swaps he had some more trouble.

So now we're replicating this because we thought when we gave it to the Harvard undergraduates though, we wanted to make sure they weren't using what we call verbal rehearsal. So if you know the color labels while we're doing the swaps, you can be thinking in your head, red, blue, yellow, green, red, blue, green, yellow, tracking the swaps. But Griffin knows the labels for his colors. It's possible he was doing that because the undergraduates, we asked them to say two plus two is four, two plus two is four, things like that, while they were watching the swaps to prevent that verbal rehearsal. So we're now replicating it with little objects he can't label. And so we're up to three little objects, they're little leaf shape things, three objects and no swaps, and he is been a hundred percent up to there, and we're just about to keep going. And the problem right now is his arthritis has kicked in and it's really hard for him to move his body to choose which one. That's one he picks to tell us which one he wants. So it's really hard to get him to choose.

Mills: Sounds like you need to take him to Times Square to play three card monte.

Pepperberg: There you go.

Mills: Well, Dr. Pepperberg, I want to thank you for joining me today. This has been really fascinating. Thank you.

Pepperberg: Oh, thank you so much for having me. This has been fun.

Mills: You can find previous episodes of Speaking of Psychology on our website at www.speakingofpsychology.org or on Apple, Spotify, YouTube, or wherever you get your podcasts. And if you like what you've heard, please subscribe and leave us a review. If you have comments or ideas for future podcasts, you can email us at [email protected]. Speaking of Psychology is produced by Lea Winerman.

Thank you for listening. For the American Psychological Association, I'm Kim Mills.