The cause was congestive heart failure, said his daughter Mary Bandura.
Dr. Bandura, who spent his entire academic career at Stanford University, was known to generations of psychology students as the author of the seminal Bobo doll studies. The substance of those studies, if not Dr. Bandura’s name, is common knowledge to anyone ever acquainted with the folly of asking a child to “do as I say, not as I do.”
In experiments conducted in the early 1960s, Dr. Bandura presented preschool-age children with film footage of adults striking, kicking and otherwise abusing an inflatable clown called Bobo. Compared with children who did not see the footage, the children exposed to the violent example were more likely to abuse Bobo dolls when given the opportunity to play with them.
To modern psychologists, and to educators and parents coached in the importance of modeling behavior, these results might seem predictable, even obvious. But at the time, Dr. Bandura’s findings were regarded as revolutionary.
“It makes a lot sense to people today because Al Bandura made it make sense,” said Laura L. Carstensen, a fellow professor of psychology at Stanford.
Under B.F. Skinner’s long-prevailing theory of behaviorism, human behavior was regarded as the result of conditioning through positive and negative reinforcement. With the Bobo doll experiments, Dr. Bandura showed a behavior such as aggression to be the product of a more complex observational learning process, in which an adult example was enough to promote a given behavior in children.
The Bobo studies — one of Dr. Bandura’s many contributions to psychology over his decades-long career — helped inform his overarching theory of social learning. He was also known for his theory of self-efficacy, which identified the belief in one’s own skills as a key factor in achievement, and for the concept of moral disengagement, which he offered as a way of explaining how people commit and justify harmful acts.
Taken together, his work influenced fields including clinical treatment for phobias, educational models in schools, child-rearing techniques and areas of psychology from emotion to human development. By the end of his career, Dr. Bandura was one of the most frequently cited psychologists of all time, often compared in his significance to Skinner, developmental psychologist Jean Piaget and psychoanalyst Sigmund Freud.
“Albert Bandura was not only one of the most influential leaders in psychology, but also one of the most important social scientists in history,” Arthur C. Evans Jr., the chief executive of the American Psychological Association, said in a statement. “His contributions have substantially influenced our understanding of human behavior today.”
In 2016, President Barack Obama awarded Dr. Bandura a National Medal of Science. The citation noted the many everyday experiences explained by his theories:
“A child blurts out a swear word after hearing a parent do the same. A teenager acts out a scene from a violent video game. A partygoer clutches a beer, because everyone else is drinking. This act of learning through observation, called ‘social learning theory,’ was conceptualized by [Dr. Bandura] in his famed Bobo doll experiment.”
Albert Bandura was born Dec. 4, 1925, in Mundare, a town of 400 inhabitants in the Canadian province of Alberta. He was the youngest and the only boy among six siblings, one of whom died in the 1918 flu pandemic. Another was killed in a hunting accident.
Dr. Bandura’s father, a Polish immigrant, laid railroad tracks. His mother, who was from Ukraine, ran a delivery service. They lived what Dr. Bandura described as a pioneer life, hoarding their savings to eventually purchase a piece of wooded land that they transformed into a working farm. Such were the challenges of their existence that they once had to sacrifice a layer of their thatched roof to feed the cattle.
Although his parents had little if any formal education, they cultivated in their children academic ambition as well as self-reliance. “The content of most textbooks is perishable,” Dr. Bandura once observed, according to a biography on his website, “but the tools of self-directedness serve one well over time.”
During high school, Dr. Bandura learned carpentry skills, which he used to support himself as a student at the University of British Columbia in Vancouver. On a whim, he enrolled in a psychology class.
“One morning, I was wasting time in the library,” he recalled. “Someone had forgotten to return a course catalog and I thumbed through it attempting to find a filler course to occupy the early time slot. I noticed a course in psychology that would serve as excellent filler. It sparked my interest and I found my career.”
Dr. Bandura received a bachelor’s degree in 1949, then moved to the United States for graduate school. He received a master’s degree in 1951 and a PhD the next year, both in psychology, from the University of Iowa. In 1953, he joined the faculty at Stanford, where he remained for the rest of his career.
Dr. Bandura was married in 1952 to Virginia Varns. She died in 2011. Survivors include two daughters, Mary Bandura of Tiverton, R.I., and Carol Bandura Cowley of Louisville, Colo.; and two grandsons.
Dr. Bandura had already studied aggression in adolescents when he embarked on the Bobo doll studies. To some observers of his work, the experiments assumed urgent importance as young people encountered increasing amounts of violence on television, in video games and on social media.
Dr. Bandura elaborated on his social cognitive theory in the volume “Social Foundations of Thought and Action” (1986). His other noted books included “Self-Efficacy: The Exercise of Control” (1997), in which he laid out his findings on what might be described in layman’s shorthand as confidence, and “Moral Disengagement: How People Do Harm and Live with Themselves” (2016).
Those two concepts converged in his deep concern over climate change, Elissa Epel, a professor of psychology at the University of California at San Francisco, observed in an email, noting yet another application of his work.
“In the climate change area, our most important tools remain building [an] individual’s personal efficacy that their behaviors matter, and even more so, building group efficacy that group change is influential,” Epel wrote, noting what she said Dr. Bandura regarded as moral disengagement among businesses that employ practices damaging to the environment.
“He was a moral figure,” said Carstensen, his Stanford colleague. “He believed that science should be directed toward improving societies.”
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