Animal Passions: Fido Loves You

Joy, despair, and the bold rush of love; experts insist such nuanced feelings are unique to humans, but some say they connect us to the rest of the animal kingdom.

By Douglas Starr, published on March 01, 2006 - last reviewed on March 12, 2008

They could almost be a couple of kids—chasing, tumbling and squealing with apparent glee. Well, almost like kids. For one thing, their squeals would be impossible to hear without the electronic device that lowers the pitch to the range of human perception. For another, black and white lab rats are not what we think of as fun-loving. Yet here they were, chirping up a storm while engaged in a bout of rough-and-tumble play.

"We studied these sounds for a couple of years without understanding they might be laughter," says Jaak Panksepp, a neuroscientist who maps animal emotions in the brain. Tickling the rats, he has found, provokes the same chirping response observed during rat play. When he momentarily stops the tickling they run to his hand, seeking more. So if you ask whether young rats enjoy playing and tickling, the answer, says Panksepp, is an "unambiguous yes."

It's not an assertion you'd expect to hear from a respected neuroscientist. But Panksepp has made a career out of an even bigger, more heretical argument—that animals have rich emotional lives. Testing rats, dogs, guinea pigs and even chickens from his lab at Bowling Green State University in Ohio since the 1980s, Panksepp has managed to trace animal sadness, fear, rage, maternal attachment and, most surprisingly, a hardwired love of play. Today, working from new digs at Washington State University, he explains that humans don't have a monopoly on emotion; rather, despair, joy and love are ancient, elemental responses that have helped all sorts of creatures survive and thrive in the natural world.

Panksepp's views were once so revolutionary that he was considered a pariah in neuroscience. But over the past several years, a cadre of neuroscientists, psychologists and animal-behaviorists has begun to overturn a centuries-old belief—that unless a creature can talk about its feelings, you can't assume it has them in the first place. Using the modern tools of brain imaging and electrical stimulation, combined with sophisticated field observations, they're finding that mammals display not only the primitive drives of fear and rage, but the softer emotions of love and nurturance, curiosity and play. In short, we've seen a philosophical shift, with the delineation between animal instinct and emotions considered uniquely human breaking down.

Emotional Chemistry

When Panksepp started out in the 1970s, his dream was a career in clinical psychology. But his inner scientist quickly took hold. He couldn't treat emotional problems unless he understood their roots, he reckoned, right down to the flux of chemicals that gave rise to feelings in the body and brain. The field was ripe for questions of the sort Panksepp posed. The opiate receptor had just been discovered, and scientists were beginning to understand that at least some of our behavior was a response to chemicals in the brain.

As far as Panksepp was concerned, animal research was the best way to learn more. He started by giving small amounts of opiates to laboratory animals, then observing the impact on primal instincts like hunger, fear and rage. But his true interest veered to the more nuanced, affective emotions—joy, grief, the ecstasy of love—which could dip or soar based on social interactions. He felt animal research was relevant here, as well. Scientists like Jane Goodall were already using words like happiness, sadness, fear and despair to describe chimps they observed in the field. At the same time, the chimp, Washoe, and the gorilla, Koko, were learning human sign language, including vocabulary for words like jealous and love. While some experts dismissed these communications as merely rote, the experiments nonetheless advanced the idea that animals had rich emotional lives.

Yet science demands hard evidence, not just impressions. So over the next thirty years, Panksepp and his graduate students conducted hundreds of experiments to get the kind of cause-and-effect measurements that would conclusively prove the case for animal emotions.

Finding Puppy Love

His first target was the separation response—a well-known behavior in which infant mammals desperately struggle and whine when removed from their mothers. In a typical experiment, Panksepp removed five-week-old puppies from their mothers and got the predictable heartrending response. When he gave tiny doses of opiates to the pups, the whining and agitation stopped. His conclusion: Attachment to mother, that most powerful and elemental of emotions, could be turned on or off by chemicals in the brain. Further experiments showed him that the range of social emotions, from the need to interact with others to the force of mother love, could be altered with delivery of neurochemicals, many of them able to comfort, soothe and abrogate loss or pain. Even the need for friends was open to manipulation: A mammal dosed with opiates would be perfectly happy to sit by itself, no matter how social the species.

He knew the chemicals were altering the animals' outward behavior and—seemingly—their inner lives. But where in the brain were those chemical reactions taking place? If Panksepp could trace the reactions to brain structures that animals and humans have in common, it would strengthen his case that not just the behaviors, but the actual emotions, are shared.

First, he tested the assumption, put forth by neuroscientists, that emotion resides in the neocortex, the top level of the brain and the seat of language and thought. To do his experiment, he removed the cortex from baby rats. If his colleagues were right, he could expect the rats to become robotic. Yet the rats grew into emotionally responsive adults, with the full range of play, curiosity and social behavior. (With their learning centers destroyed, of course, they failed at navigating a maze.)