Why are humans such social creatures? In this episode, Ashley Judd explores the origins of social behavior by taking you inside the minds of a troop of baboons living in Botswana’s Okovango Delta.
Why are humans such social creatures? In this episode, Ashley Judd explores the origins of social behavior by taking you inside the minds of a troop of baboons living in Botswana’s Okovango Delta.
Further reading (and listening)
About The Leakey Foundation
The Leakey Foundation is a nonprofit organization dedicated to funding human origins research and sharing discoveries. The Foundation was established in 1968 to fund work at the forefront of fossil and primate studies and provide opportunities for a global community of scientists. Learn more at leakeyfoundation.org.
Discovering Us: 50 Great Discoveries in Human Origins
In 50 lively and up-to-the-minute essays illustrated with full-color photographs, Discovering Us: 50 Great Discoveries in Human Origins presents stories of the most exciting and groundbreaking surprises revealed by human origins research.
Prepared in consultation with leading experts and written by Evan Hadingham, senior science editor for NOVA, Discovering Us features stunning photographs, some taken at the actual moment that groundbreaking discoveries were made. The book presents a highly accessible account of the latest scientific insights into the ultimate question of humanity’s origins. Discovering Us was published by Signature Books.
Find Discovering Us at your local library, bookstore, or amazon.com.
Show Credits:
Discovering Us was made possible by generous support from Camilla and George Smith, the Ann and Gordon Getty Foundation, and the Joan and Arnold Travis Education Fund.
Meredith Johnson:
This is Discovering Us from The Leakey Foundation and Signature Books … an audio companion to the book Discovering Us: 50 Great Discoveries in Human Origins. Written by Evan Hadingham and read for you by Ashley Judd.
I’m your host, Meredith Johnson.
In this installment of Discovering Us, we’re going on a journey inside the minds of one of our primate relatives.
Baboons have fascinating social lives that scientists look to in order to understand more about how humans became such social creatures.
The discovery Ashley Judd will share with you today comes from the work of a husband and wife team of scientists - Leakey Foundation grantees Dorothy Cheney and Robert Seyfarth. Their groundbreaking work in Botswana’s Okovango Delta helped us understand the origins of social behavior.
Here’s Ashley Judd…
Ashley Judd
Inside baboon minds
Royal, a grumpy old male, is one of an 80-strong troop of baboons in the Moremi Game Reserve in Botswana.
Like all baboons, he belongs to a complex, highly competitive society, and pays constant attention to the social cues around him. His world, much like ours, depends on communication, and understanding its rules sheds light on our own social evolution.
Today has been uneventful until, somewhere off in the bushes to his right, Royal hears the unmistakable whoop that female baboons make after mating. Her call is of little interest because Royal knows it belongs to Jackalberry, the partner of Cassius, a high-ranking male who guards her from other suitors.
But then there is a surprise. To Royal’s left, far away from Jackalberry, comes the familiar grunt of Cassius. Royal seems to ponder the implications for a moment: could Jackalberry be cheating on Cassius with somebody else? Perhaps hoping for some action himself, he heads off in her direction.
Sadly for Royal, instead of a receptive female hidden in the bushes, he finds the true source of Jackalberry’s call: a loudspeaker planted by humans.
Why would researchers play a trick on a crusty old baboon? Dorothy Cheney (chay-nee) and Robert Seyfarth (say-farth), a husband-and-wife team of primatologists, spent 16 years at the Moremi Reserve living in tents, occasionally being chased into trees by lions, and devising ingenious experiments that reveal how baboon minds work.
Baboon society is rigidly organized around matrilineal families, and females stay throughout their lives in the group where they were born.
Social status is inherited and long-lasting, but through sheer force of personality, and by grooming others - a low-ranking female can make alliances and friendships with her superiors.
These ties offer protection from predators and aggressive males, boosting survival and reproductive success.
Cheney and Seyfarth wrote that “monkey society is governed by the same two general rules that governed the behavior of women in so many 19th-century novels. Stay loyal to your relatives...but also try to ingratiate yourself with the members of high-ranking families.”
Cheney and Seyfarth spent months building a library of baboon calls. By playing their recordings back from hidden loudspeakers, they discovered that an individual recognizes the voices of all 80 members of the troop.
Then they embarked on experiments that violate the normal rules of baboon communication.
For example, the social wheels of baboon society are greased by a strict protocol of how they address one another.
When a high-ranking animal encounters a lower-ranked one, it sometimes issues a standard “threat grunt;” the lower-ranked animal typically responds with a deferential scream.
With the help of their recording library, the researchers would scramble the order of these calls or combine them in unusual ways, then measure the surprised reactions of baboon listeners.
Years of similar “playback” experiments gave Cheney and Seyfarth extensive data on the social knowledge and expectations of each animal.
They concluded that baboons understand not only their own place in the hierarchy but the status and relationships of everyone else, too.
As the incident with Royal revealed, they are keenly interested in transient day-to-day shifts in relation- ships in a way irresistibly reminiscent of our own obsessions with gossip on Facebook and Twitter.
We, too, are highly social primates. Cheney and Seyfarth argue that the challenge of life in a social group shaped the evolution of our minds no less than it did baboons’.
Yet human and baboon minds are crucially different. Despite deep understanding of their social network, baboons seem lacking in empathy; they apparently do not grasp what other animals know or how they are feeling, which psychologists refer to as “theory of mind.”
According to Cheney and Seyfarth, a baboons’ theory of mind might best be described as a vague intuition about other animals’ intentions.
They observed many striking examples of this deficiency. In one incident, flooding drove the adults in the troop to swim to another island, leaving nearly all the young animals stranded behind them. While the juveniles emitted distress calls that were clearly heard by the adults, only one adult ever responded.
For three days, the vulnerable juveniles banded together to survive, finally braving the water to swim across and reunite with the group. In this case and many others, baboons show little interest in the mental states and needs of others, even their own infants.
Another contrast can be found in the limitations of their vocal output.
The playback experiments clearly demonstrate that they can recognize the order of two sounds and attach meaning to it, almost like a sentence.
Despite this basic grasp of syntax, their calls consist only of single sounds that are never combined to express new meaning—the essence of human language.
“The ability to think in sentences does not lead them to speak in sentences,” Cheney and Seyfarth noted.
“Under natural conditions they certainly have interesting vocalizations. But if they have such a rich understanding of other animals’ calls, why do they produce so few? It’s a real puzzle, because the same animal is both a creative listener and a very limited speaker. Where does this limitation come from? The speech apparatus? The brain? Or is it just a matter of motivation?”
After years of dedicated and inventive research, Cheney and Seyfarth had no clear answers to the riddle. Yet their painstaking experiments suggested that some of the foundations of language, one of humanity’s most significant evolutionary advances, were already laid down among the common ancestors of baboons and humans, dating back many millions of years in our shared past.
[MUSIC rises and then ducks under closing credits]
Meredith Johnson
Discovering Us: 50 Great Discoveries in Human Origins was written for The Leakey Foundation by Evan Hadingham. It was published by Signature Books. The stories are read for you by Ashley Judd.
All the episodes of this audio-companion are available to listen to right now! Make sure to subscribe and share this series with a friend.
You can buy a copy of Discovering Us at your local bookstore or wherever you buy books. There’s a link in the shownotes.
The Leakey Foundation is a nonprofit organization dedicated to funding human origins research and sharing discoveries. The science you heard about today was made possible by Leakey Foundation supporters. Visit our website to learn how you can get involved. Go to leakeyfoundation.org. That’s l-e-a-k-e-y foundation dot org.
If you want to hear more about the research in today’s story, check out our Origin Stories podcast. Dr. Cheney and Dr. Seyfarth tell their story on episode 6. And if you want to learn about new research with baboons, subscribe to our YouTube channel to watch episodes of our web series Lunch Break Science! Links are in your shownotes.
This project was made possible by generous support from Camilla and George Smith, the Joan and Arnold Travis Education Fund, and the Ann and Gordon Getty Foundation