Prof. Jerome Kagan, a Harvard psychologist whose research into temperament found that shy infants often grow up to be anxious and fearful adults because of their biological nature as well as the way they were nurtured, died on May 10 in Chapel Hill, N.C. He was 92.
Jane Kagan, his daughter, said he had been visiting her for several months in North Carolina, where he had planned to relocate from his home in Belmont, Mass., outside Boston.
Prof. Daniel Gilbert, another Harvard psychologist and author, described Professor Kagan in an email as “one of the most influential psychologists of the 20th century.”
“His research was not only original and groundbreaking,” he added, “but also prescient, foreshadowing the coming merger of psychology and biology in its attempt to link behavior to the brain.”
Professor Kagan argued in more than two dozen books, including the widely praised “The Nature of the Child” (1984), that some children were genetically wired to worry and that they proved to be more resilient than expected as they passed from one stage of maturity to another. He also contended that the specifics of parenting were often not as crucial to a child’s future as parents think, although the child’s natural predisposition to be shy or exuberant could be altered by experience.
His conclusions that some children may be born predisposed to a particular temperament may have come as some relief to the many parents of baby boomers who had rigidly followed the nurturing advice of Dr. Benjamin Spock but nonetheless raised a generation of rebellious teenagers in the 1960s.
Professor Kagan and his collaborators, including Howard A. Moss and Nancy C. Snidman, pioneered the reintroduction of physiology as a determinant of psychological characteristics that could be measured in the brain.
They derived their conclusions from lengthy studies that started with the videotaped reactions of toddlers and infants as young as 4 months to various stimuli — unfamiliar objects, people and situations — and correlated those reactions to their temperament as teenagers and beyond, as measured in interviews.
The wary ones who were subdued, shy and hovered around their mothers or who fussed, thrashed around and cried — about 15 percent of the total — tended to become anxious, inhibited adults. Another 15 percent who were ebullient as infants and embraced every new toy and interviewer tended to develop into fearless children and adolescents.
Professor Kagan acknowledged that as an ideological liberal he had originally believed that all individuals were capable of achieving similar goals if afforded the same opportunities. “I was so resistant to awarding biology much influence,” he wrote.
But he also concluded that properly run educational remedial programs were valuable because, except for the tiny number with acute brain damage, a vast majority of children, regardless of race or class, had the ability to master the intellectual skills that schools require as long as the students were instilled with confidence that they could succeed.
Professor Kagan reassured women who worked outside the home that infants in day care barely differed from those who were home with their mothers, in terms of attachment, separation, cognitive functioning and language.
His “The Nature of the Child” drew acclaim because, as the psychologist and writer Daniel Goleman wrote in The New York Times Book Review, Professor Kagan was “among those rare men of science who have also mastered the essayist’s art.”
Jerome Kagan, a grandson of immigrants from Eastern Europe, was born on Feb. 25, 1929, in Newark to Joseph and Myrtle (Liebermann) Kagan, who ran a shoe store in Rahway, N.J.
“My memory is that I was an anxious child” who stuttered during his first two years of elementary school, he recalled in an oral history interview in 1993 with the Society for Research in Child Development.
In those days, parents and psychologists understood the source of many anxieties to be experiential. That proved intriguing to him.
“During the 1940s and ’50s, many citizens and social scientists believed that the main, if not the only, cause of the problems that plague our species were childhood experiences,” he told The Harvard Gazette in 2010.
“It followed,” he added, “that anyone who discovered the specific experiences that led to a mental illness, crime or school failure would be a hero doing God’s work. Who would not entertain the idea of becoming a child psychologist, given this zeitgeist?”
He graduated with a bachelor’s degree in biology and psychology from Rutgers University in 1950 and received a doctorate in psychology in 1954 from Yale, where he had been recruited to study by Prof. Frank A. Beach, a prominent psychologist.
He taught briefly at Ohio State, was drafted into the Army and conducted research at the military hospital at West Point. He then joined the Fels Research Institute in Yellow Springs, Ohio, where his and Dr. Moss’s work resulted in a book on child development, “Birth to Maturity” (1962).
He accepted an offer by Harvard to help establish its first human development program and was named a psychology professor there in 1964. He remained at Harvard, except for a year of fieldwork in Guatemala, until his retirement in 2005.
In 1963, Professor Kagan was awarded the American Psychiatric Association’s Hofheimer Prize; in 1995, he received the American Psychological Association’s G. Stanley Hall Award.
His other books include “The Growth of the Child: Reflections on Human Development” (1978), “Galen’s Prophecy: Temperament in Human Nature” (1994) and “A Trio of Pursuits: Puzzles in Human Development” (2021).
In addition to his daughter, Jane, he is survived by a granddaughter and a great-grandson. His wife, Cele (Katzman) Kagan, whom he married in 1951, died in 2020.
Whatever inhibitions Professor Kagan had as an anxious child with a stutter, he apparently outgrew them.
“Every encounter with Jerry began with ‘I just learned something amazing!’ after which he would prove he had,” Professor Gilbert, of Harvard, said. “He grasped your hand and your shoulder and pulled you toward him, and he wouldn’t let go of either until you’d agreed that this new fact, idea or discovery was indeed the most fantastic thing you’d ever contemplated.
“And then he’d say, ‘So what have you learned lately?’ and expect you to dazzle him in return.”