Study: Animals experience emotions like humans

The research team was led by Dr Marcela Benítez, Assistant Professor of Anthropology at Emory University.

“As far as we know, this is the first assessment of how animal behaviour researchers from different disciplines think about emotions and consciousness in non-human animals,” said Professor Benítez.

Quantifying Animal Emotions

The study shows that the majority of researchers attribute emotions to non-human primates (98%), mammals (89%), birds (78%), and even octopuses, squid (72%) and fish (53%).

Incredibly, feelings are even attributed to invertebrates (71%) and insects (67%).

Anthropomorphism – the projection of human experiences onto animals – and anthropodenial – the denial of any human characteristics in animals – were identified as dangers in animal behaviour research.

Surprisingly, 89% of respondents considered anthropodenial more problematic, compared to only 49% who saw anthropomorphism as a risk. “That seems to be a significant shift,” said Professor Benítez.

History of Emotion Research in Animals

The question of whether animals experience emotions has occupied thinkers since Aristotle and Descartes.

Charles Darwin also addressed this topic, writing that “the lower animals, like man, evidently feel pleasure and pain, happiness and misery.”

However, mid-20th-century behavioural theorists rejected the study of animal emotions, as such feelings were considered scientifically unquantifiable.

The Study of Animal Cognition

The late primatologist Frans de Waal, professor emeritus of psychology at Emory College, revolutionised research into animals' cognitive abilities through his profound studies.

“Frans de Waal definitely helped push the door open,” says Benítez, who credits him with giving new scientists the opportunity to question the inner lives of animals.

Matthew Zipple, a neurobiologist at Cornell University's Laboratory for Animal Social Evolution and Recognition, is the lead author of the study. Mackenzie Webster, a postdoctoral researcher at the Emory institute, and philosopher Caleb Hazelwood were also part of the team.

Professor Benítez, whose research focuses on cooperation and other social behaviours in capuchin monkeys, acknowledges the influence of de Waal's work on her career.

“A key component of cooperation is often the formation of emotional bonds with one another. So I can't shy away from taking emotions into account in my research,” she says.

Survey on emotions in animals

To investigate how researchers perceive emotions in animals, Professor Benítez and her team developed a carefully designed survey, which was distributed to graduate programmes in animal behaviour research across various disciplines.

Respondents came from a range of fields – behavioural ecologists, evolutionary biologists, neuroscientists, cognitive psychologists, biological psychologists and others.

Challenges in defining emotions in animals

Towards the end of the survey, respondents were asked to define “emotions”.

“I don't have a clear definition either,” said Benítez. “I see emotions as a kind of internal process that responds to external stimuli and affects how a situation is perceived. I start from the most basic definition because it allows us to study this capacity in non-human primates.”

Animal studies present particular challenges. A major problem with laboratory experiments is replicating the animal's natural environment. In the wild, it is difficult to plan and control the experiment.

Innovative solutions to age-old challenges

Professor Benítez is doing pioneering work with a new approach to close this gap. She is co-director of the Capuchins de Taboga Costa Rica project, which studies both captive and wild-living capuchin monkeys.

Her team uses AI techniques, facial recognition software and touchscreen computers on presentation platforms in the wild to better understand the behaviour of capuchin monkeys.

Ethical implications of animal studies

Research into the consciousness and emotions of animals extends beyond the realm of science and ethics, challenging moral considerations and the treatment of animals in various fields.

Researchers must navigate complex ethical terrain, striking a balance between scientific research and the welfare and respectful treatment of the animals involved.

The recognition that animals may have emotions similar to those of humans calls for humane treatment protocols and raises questions about the ethical implications of using animals in research, entertainment and agriculture.

As research in this field progresses, an ongoing dialogue remains necessary regarding scientists' responsibility to advocate for policies that protect animals' rights while advancing scientific knowledge.

The future of emotion research in animals

The future of emotion research in animals promises even more advanced methods and interdisciplinary collaborations that will push the boundaries of our understanding.

As AI and machine learning continue to develop, these technologies offer new opportunities to analyse and interpret animal behaviour on an unprecedented scale, enabling deeper insights into their emotional lives.

Furthermore, fostering collaboration between behavioural scientists, technologists, ethicists and policymakers can help develop innovative approaches that are both scientifically sound and ethically responsible.

Taking these future directions into account can drive the field towards a more holistic understanding of non-human animals, ultimately transforming the way society views and interacts with the animal world.

"We have only scratched the surface in exploring what animals are capable of," said Professor Benítez.

"Understanding the evolution of emotions is an essential part of understanding our own ancestry. In what ways are we a unique species? It's an exciting time, because new methods can help us better understand how an animal feels and how this relates to the decisions it makes."

The study was published in the journal Royal Society Open Science.

You can help all animals and our planet with compassion. Choose compassion on your plate and in your glass. Go vegan.