1967
Dorado Beach, Puerto Rico
At a tropical hotel, under a blazing late-June sun, David Rosenthal—the researcher from the National Institute of Mental Health who had studied the Genain quadruplets and concluded that heredity and the environment must be working together—joined some of the most prominent thinkers in psychiatry at an academic summit about the continuing debate over nature and nurture and schizophrenia. Nothing like this had happened before, but a meeting seemed necessary now.
By the 1960s, the Thorazine revolution had raised the stakes in the debate. To those favoring genetics, or nature, the impact of neuroleptic drugs proved, at the very least, that schizophrenia was a biological process. But for the therapists on the nurture side, Thorazine and the like were just symptom suppressors—glorified tranquilizers—and there could be no substitute for probing the unconscious impulses that must have caused the disease. This conference, then, was a cautious attempt to break the impasse. While Rosenthal, as NIMH’s chief researcher of schizophrenia, was one of the event’s organizers, the psychotherapy camp was well represented, too—by, among others, Theodore Lidz, the Yale psychiatrist and pioneer in the study of family dynamics. The conference title, “The Transmission of Schizophrenia,” was diplomatically worded; transmission was thought not to tip the scales in favor of one side or the other, the biologists or the talk therapists. Even the setting—Dorado Beach, Puerto Rico—seemed meant to ease tension and, just maybe, help build a lasting peace.
In the three years since he had published his book on the Genain family, Rosenthal had been approaching the nature-nurture question from a different angle. Toward the end of his work with the quadruplets, he had begun to see all too clearly the limitations of studying siblings who grew up in the same environment. Instead, he started to wonder what would happen to a child with a family history of schizophrenia if you raised that child away from her family environment. Who, in other words, would be more likely to develop schizophrenia: a genetically vulnerable child who grew up among her blood relatives, or a similar child who had been adopted and raised by people who did not share her genes? Now, in Dorado Beach, he was ready to announce the first of his findings. Here, it seemed to him, was proof that nature, not nurture, won the argument.
Rosenthal and Seymour Kety, NIMH’s director of research, found a sample population for their study in Denmark—a nation that many genetics researchers had come to adore, thanks to that country’s excellent medical record-keeping and willingness to contribute those records to scientific research. They were able to search the records for people who were adopted and then developed schizophrenia. Then they dug into the health records of the families who had adopted them, searching for correlations—to eliminate the possibility that an outsized number of the mentally ill adoptees happened to be adopted into families with a lot of mental illness. Finally, they compared their adoptees to a control group—schizophrenia patients who grew up in their own families. The end goal: See which scenario, nature or nurture, seemed to produce a greater incidence of schizophrenia.
It wasn’t even close. At Dorado Beach, Rosenthal declared that biology, not proximity to people with a history of schizophrenia, appeared to explain nearly every single documented instance of the illness. Where you grew up, or the people who raised you, seemed to have nothing to do with it at all. On the whole, families with a history of schizophrenia seemed more than four times as likely as the rest of the population to pass along the condition to future generations—even if, as ever, the illness rarely passed straight from parent to child.
This conclusion spoke volumes about how the disease wandered and meandered through families—and that, alone, would have been stunning. But in their analysis of adoption cases, Rosenthal and Kety also found no evidence to support the opposing, “nurture” view—that schizophrenia could be transmitted from a mentally ill parent to an adopted child who did not share the adoptive family’s genetic history. Schizophrenia, he concluded, simply can’t be imposed or inflicted on someone who is not genetically predisposed to develop the condition.
Rosenthal thought he’d finally settled the argument—and, for good measure, discredited the idea that bad parenting created the disease. At the conference, he found at least one kindred spirit: a young psychiatrist named Irving Gottesman, who, with his coauthor, James Shields, had just published a study that reached a very similar conclusion. Their completed work, “A Polygenic Theory of Schizophrenia,” argued that schizophrenia could be caused by not just one gene but a chorus of many genes, working in tandem with, or perhaps activated by, various environmental factors. Their proof involved twins, but with a twist: Instead of conceiving the illness as the handiwork of one dominant gene or two recessive genes, they proposed that there exists a “liability threshold” for genetic illnesses—a theoretical point beyond which some people might develop the illness. The causes that would collaborate to bring someone close to this threshold might be genetic or environmental—a family history of the disease and a traumatic childhood, perhaps. But without the critical mass of these factors, a person might live their entire life with a genetic legacy of schizophrenia and not become symptomatic.
Gottesman and Shields’s theory became known as the “diathesis-stress hypothesis”—nature, activated by nurture. Decades later, their work would be seen as phenomenally prescient, the real beginning of the end of the great argument that had stretched back to Freud and Jung. Seen one way, the diathesis-stress hypothesis might even be interpreted as a compromise between the nature and nurture camps: If the theory held, then it seemed logical that Thorazine and other neuroleptic drugs, regardless of how they functioned, could only be one part of any lasting treatment of the illness.
But at Dorado Beach, the idea met with the usual resistance. Even one of Rosenthal’s own colleagues from NIMH argued instead that a childhood spent in chaos or poverty could be one cause: The larger the city, new studies suggested, the more social class had a relationship to schizophrenia. But that same colleague acknowledged a causality question: Does poverty cause schizophrenia, or does congenital mental illness throw families into poverty?
The schizophrenogenic mother was back, too. A speaker from the University of Helsinki used his time to pillory mothers “embittered, aggressive and devoid of natural warmth” and “anxious and insecure, often with obsessive features.” And yet the Helsinki therapist could not explain why, if the mother was to blame, some children of the same mother fall ill with schizophrenia while others do not. He had only his belief that bad mothering must be the answer.
Then came Theodore Lidz with his family dynamics explanation: A child can fail to mature adequately, he declared, if “he perceives very faulty nurturance in his first few years, or he is seriously traumatized.” The Yale psychiatrist cited no data to support this position, just his personal work with families affected by schizophrenia.
A week went by like this until, on July 1, the conference’s last day, it fell on Rosenthal, the organizer, to sum up the state of the field. He treaded lightly, opening with a joke. The heredity-environment controversy in schizophrenia, he said, reminded him of a “white-shirted French duel,” in which the duelers “managed to avoid each other so thoroughly that they never exposed themselves even to the danger of catching cold.” Remaining diplomatic, Rosenthal said that he saw it as a positive sign that everyone was able to come together at all. “This week we have been able to sit here day after day and listen to people expounding ideas both compatible and contrary to our own,” he said, “and far from catching any dread affliction, the only thing we have caught, I hope, is the spirit of earnest concern about the other man’s data and opinions.”
There would be no real reconciliation anytime soon. Three years later, the chief of the family studies section at NIMH, David Reiss, also a participant at Dorado Beach, would still be referring to the geneticists and the environmentalists as “warring camps.” Families like the Galvins, meanwhile, continued to live at the mercy of a mental health profession still caught up in a debate that came nowhere close to helping them. But there was a good reason for this impasse, one that Rosenthal acknowledged in his closing remarks—a mystery that would take another generation to even start to be solved.
The good news, Rosenthal said, was that “all the reasonable doubts that had been raised in past years have now been answered, and the case for heredity has held up convincingly.” This conference, he predicted, “could be remembered as the time when it was definitely and openly agreed by our foremost students of family interaction that heredity is implicated in the development of schizophrenia.”
But that concession only raised a more puzzling question. “In the strictest sense, it is not schizophrenia that is inherited,” he said. “It is clear that not everybody who harbors the genes develops schizophrenia.” Schizophrenia was definitely genetic, but not always passed down. And so they all were still left wondering: How could this be?
“The genes that are implicated,” Rosenthal said, “produce an effect whose nature we have not yet been able to fathom.”