You defined seven fundamental emotions, all spelled with capital letters in your academic papers. Why?
These are the emotional primes, the primary-process emotional systems associated with specific brain networks and specifically designated in the brain-stimulation studies of emotions. They are seeking, RAGE, FEAR, LUST. CARE, PANIC/GRIEF,and PLAY. These are capitalized because the evidence supports a category of evolutionarily homologous experiences, equivalent across different species of mammals.
In your next career move, you wound up at Bowling Green State
University in Ohio in 1972. Why there?
It had a unique lab run by someone I found totally fascinating: John Paul Scott, a biologist in the psychology department who had done more work than anyone else on social attachments in dogs. Attachment is the bond of selective preference between a mother and a child, whatever the species. Mother dogs and their pups bond, mother sheep and their lambs bond, and so forth. When a real bond has been established, the young selectively prefer their own mother, and follow her around persistently in order to feel comfortable. Conversely, the mother will shower all her devotion on just her own babies. When this attachment bond is broken, the young cry and cry until reunited with the mother; this is the panic system in action. Animals that grow up crying the most because they are separated from their mothers for the longest are generally maladjusted. Scott insisted that attachment had to be studied biologically, but no one knew how.
Then you found a way to study attachment. How did you do it?
Serendipitously, that was the moment, in 1973, that scientists discovered the opiate receptor—the first neurochemical receptor in the brain. The day I heard that, I said, this has got to be the attachment mechanism. Opiate addiction is another phenomenon that creates a powerful bond. We call it by a different name, addiction, but it is activated via a molecule that produces good feelings, and mom produces a lot of good feelings in the young ones, too. They feel comfortable, they feel soothed, and opioids have that same property, psychologically.
How could you test the idea that social attachment is related to
I had the insight that if you wanted to understand attachment, you would have to study crying. My first successful experiments used dogs. We took young pups and gave them morphine. Then we removed them from their mothers. The more morphine they got, the less they cried and the quieter they were. They sat alone and were satisfied, as if the mother was right there. Significantly, we could comfort the animals only with opiates like morphine, not with the types of agents often used to quell anxiety, the benzodiazepines. So we knew the crying wasn’t a physical fear. As with aggression, there were two kinds of anxiety systems. One was fear that a predator would attack, and the other was panic over separation.
What was the response to your discovery?
We had to use emotional language to describe what we found, and the bottom line is we simply got rejected as being crazy. For the next 10 years, all we heard was, you’re just sedating animals, what the hell? We don’t have to pay attention to you. So we didn’t get a penny for that work. When you don’t have a penny to pursue research, that’s a very expensive canine laboratory. After John Paul Scott retired, I was given the job of saving the canine research facility. We must have written at least half a dozen grant proposals, and the message was clear: We’re not gonna get funded no matter what we do. Dogs were the perfect species for the study of social attachment, but no one got it. The best canine behavioral research laboratory, and the last one in the country, died with me. I was incredibly disappointed.
So what then—you turned back to rats?
No, because rats don’t cry. They give a distress call, but it’s not about social separation; it’s just, I’m cold, I’m out of the nest. But the guinea pig showed real vocalizations, and we found, yes, they also quiet down with opiates just like dogs. So Barbara Herman, one of my first Ph.D. students, took on the project of mapping the crying system in the brain of guinea pigs. That system converged in the periaqueductal gray area, an ancient area of the brain. By putting electrodes there, you could get the animals to make very intense separation calls. The calls continued as you put electrodes into the medial thalamus and the basal ganglia, areas seen as part of an anxiety system by fear researchers. I kept saying, this isn’t fear, this is a different anxiety. They didn’t care to listen because they never even thought about the separation call. But we mapped the anatomy. By 1978 we had mapped the attachment system in three species in all.