Professor Emeritus of Ecology and Evolutionary Biology at the University of Colorado, Boulder, Author of Rewilding Our Hearts: Building Pathways of Compassion and Coexistence and The Animals’ Agenda: Freedom, Compassion, and Coexistence in the Human Age
I think that many or most emotions are contagious, but for me the two that really grab me are joy/happiness and grief/sadness. I study dogs and when I see dogs playing I want to jump right in, as do other dogs. It’s that contagious. I can feel their passion and glee, likely because we’re all mammals and share much of the same neural wiring and neurochemicals underlying joy and happiness. Likewise, I can feel when another animal, including a human animal, is feeling down and out.
I once came upon a herd of wild elephants living in the Samburu Reserve in northern Kenya. I hadn’t seen many wild elephants before but I could feel their grief. They just didn’t look happy and ‘up.’ I had the pleasure of being there with Dr. Iain Douglas-Hamilton, one of the world’s leading elephant experts, and I asked Iain if something was wrong. He told me that the matriarch of that particular group — the oldest female who was their leader and social glue and keeper of traditional knowledge — had recently passed away. And yes, the other members of the herd were mourning and depressed and lost without the wise elder.
Associate Professor of Evolutionary Anthropology at Duke University, Member of Center for Cognitive Neuroscience, Duke Institute for Brain Sciences
I think the most interesting work is on contagious yawning. What we have seen is that across primates individuals will yawn in response to others yawning – but the likelihood of them yawning is linked to their relationship with the individual who yawns. Friends and family of an individual are more likely to illicit contagious yawning than a rival or a stranger unrelated to them. The same seems to be true for humans – I find it fun to watch people in meetings to see who yawns contagiously as a gauge of relationship quality.
If one bonobo screams in alarm another bonobo will also [scream]. It is hard to know why the second bonobo is alarmed. Is it because they saw the threat and also became fearful? Or they simply called in a fearful way reflexively when another group member calls in fearful way, but don’t actually experience the fear unless they encounter the threat as well? This is much harder to know.
Responses of fear, anger, disgust, and pleasure all clearly have an important role in the social life of any primate and even have predictable behavioural responses, dedicated facial expressions and musculature. More abstract notions of emotional states like pride, shame, hate, etc. do not really have a morphology or nonverbal behaviour specific to them that would allow us to easily measure in nonhumans (or even non-verbal human infants).
That said, taking my science hat off for a moment, animals definitely fall in love and feel jealousy! And yes, those emotions are contagious.