“To our knowledge, this is the first assessment of how animal behavior researchers from a range of disciplines think about emotion and consciousness in non-human animals,” says Marcela Benítez, assistant professor of anthropology at Emory University and corresponding author of the study. paper. “It gives us a snapshot in time so that 20 years from now we can review how scientific experts have changed their views.”

Most survey respondents attributed emotions to “most” or “all or almost all” non-human primates (98%), other mammals (89%), birds (78%), octopus, squid and cuttlefish (72%). and fish (53%). And most respondents attributed emotions to at least some members of every taxonomic group of animals considered, including insects (67%) and other invertebrates (71%).

The survey also included questions about the risks in animal behavioral research of anthropomorphism (incorrectly projecting human experience onto animals) and anthropodeny (the willful blindness to any human characteristics of animals).

“It is surprising that 89% of respondents thought that anthropodenism was problematic in animal behavioral research, compared to only 49% who believed that anthropodenism posed a risk,” says Benítez. “It seems like a big change.”

Anthromorphism, she notes, has long been a primary argument against those who attribute sentience to animals.

The first author of the current paper is Matthew Zipple, a neurobiologist at Cornell University’s Laboratory for Animal Social Cognition and Evolution. Co-authors include Mackenzie Webster, an Emory postdoctoral fellow who studies cognition in nonhuman primates, and Caleb Hazelwood, a philosopher at Duke University.

Since ancient times, philosophers have pondered the seemingly simple question of whether animals experience emotions. Aristotle believed that animals and humans shared similar emotions, while Descartes argued that animals were more like machines, without the capacity for emotions or consciousness.

In the mid-1800s, the famous naturalist Charles Darwin wrote that “the lower animals, like man, evidently feel pleasure and pain, happiness and misery.” Around mid 20’s^th-century, however, leading behavioral theorists disparaged the idea of ​​studying animal emotions because, even if they existed, they were unmeasurable and scientifically unverifiable.

The late primatologist Frans de Waal, an Emory professor emeritus of psychology, helped change that dynamic with his groundbreaking studies of animal cognition. From de Waal’s 1982 book The Politics of Chimpanzees to 2019’s Mother’s Last Hug: Animal Emotions and What They Tell Us About Ourselves, attitudes about whether animals might have thoughts worthy of scientific exploration have changed dramatic.

“Frans de Waal certainly helped open the door,” says Benítez. “He gave a new generation of scientists permission to ask questions about the inner lives of animals.”

Benítez’s work lies at the intersection of anthropology, psychology, and evolutionary biology. He is currently studying cooperation and other social behaviors in capuchin monkeys. “A key component of cooperation often involves forming emotional bonds with each other,” she says. “So I can’t be shy about considering emotions in my research.”

She did a postdoctoral fellowship in the lab of Sarah Brosnan, an Emory PhD graduate and student of de Waal’s, when she served as director of the Living Links Center for the Advanced Study of Apes and Human Evolution at Emory’s National Primate Research Center . Brosnan is now a professor of psychology at Georgia State University, where he investigates the evolution of cooperation, decision-making, and economic behavior among primates.

Benítez says de Waal’s legacy was a major reason she enrolled in college at Emory, where she feels she is following in his footsteps.

De Waal’s popular and best-selling books also shaped the public’s perception of animal minds.

Several of the Emory graduate students who now work in Benítez’s Laboratory of Primate Social Cognition and Behavior read about de Waal’s work when they were younger. “That inspired him to want to study animal cognition,” she says. “His legacy is truly widespread.”

As the field grew, Benítez and his colleagues wanted to quantify animal behavior researchers’ perceptions of the taxonomic distribution of animal emotionality. They developed a survey with multiple-choice questions, free-form text fields, and rating scales and sent it to leading graduate programs in animal behavior research across disciplines. They also posted poll requests on X, aimed at researchers in these fields.

The 100 respondents to the survey spanned a wide range of specialties, including behavioral ecologists, evolutionary biologists, neuroscientists, biological anthropologists, cognitive psychologists, and biological psychologists. These included graduate students (45), professors (28), postdoctoral fellows (20), retired professors (2), other doctoral researchers (3), and undergraduate students (2).

The most common animal taxa studied among respondents were birds (43%), nonhuman primates (32%), and other mammals, although each of the taxa the survey asked respondents to rate was studied by the few members of the sample. .

The survey defined animal displays of consciousness in its most basic form, meaning that they are aware of their own existence. Most respondents attributed consciousness to a wide taxonomic range of animals, although in slightly smaller majorities compared to emotions.

Near the end of the survey, respondents were asked to define the emotion.

Just over half of their definitions referred to emotions as a response to internal or external stimuli. Most also referred to emotions as subjective experiences or related to consciousness or mindset. And 40% of responses identified emotions as working to motivate behaviors.

Only 81 of the 100 survey respondents provided a definition, perhaps due to the challenge of verbalizing a job description.

“I don’t have a clear definition either,” says Benítez. “I see emotions as a kind of internal process of response to external stimuli, which has an impact on how a situation is perceived. I move to the most basic definition because it allows us to explore this ability in non-human primates.”

Even in human studies, Benítez adds, it is a challenge to determine which biological markers to measure and how to adequately describe and quantify something as complex and variable as emotions. They can include everything from instinctive reactions of disgust or fear to deep feelings of affection and empathy for others.

Animal studies are further complicated by the fact that researchers cannot ask an animal how it feels.

And while animal experiments in laboratories can be tightly controlled, the results can be skewed because the animal is not interacting in its natural environment. Animal behavioral experiments in the wild provide valid social and ecological contexts, but are difficult to design and control.

“I’m trying to reduce that gap,” says Benítez. Her work is unique in that she studies behavior in both a captive population of tufted capuchins and wild white-faced capuchins as co-director of the Capuchins de Taboga Costa Rica project in Liberia, Costa Rica.

Benítez and her collaborators at the Universidad Technica Nacional are beginning to implement AI techniques, facial recognition software and touch-screen computers on presentation platforms in the wild. These tools can help them solve many questions about the behavior of capuchin monkeys, including how they decide whether to cooperate or compete with each other as they interact in their natural world.

“We’ve only scratched the surface of exploring what animals are capable of experiencing,” says Benítez. “It’s an exciting time as new methods are being developed that can help us better understand how an animal might be feeling and how that relates to the decisions they make.”

“As an anthropologist,” she adds, “a big part of my desire to understand the inner lives of animals is to better understand our own ancestors. How are we a unique species? Understanding the evolution of emotions is integral to this question. .”