Robert R. Provine, a neuroscientist who brought scientific rigor to the study of laughter, yawns, hiccups and other universal human behaviors that had previously gone largely unexplored, died Oct. 17 at a hospital in Baltimore. He was 76.

The cause was complications from non-Hodgkin’s lymphoma, said his wife, Helen Weems. Dr. Provine had spent four decades as a psychology professor at the University of Maryland at Baltimore County before his retirement in 2013. He continued to teach at the university in recent years as a professor emeritus.

Dr. Provine embodied the spirit of the popular scientist, one who takes his or her pursuits out of the laboratory and into the public square, from university libraries to public libraries, and from lecture halls to radio and television.

He was the author of two books for popular audiences, “Laughter: A Scientific Investigation” (2000) and “Curious Behavior: Yawning, Laughing, Hiccupping, and Beyond” (2012). The publication New Scientist described him as “the man behind the first research into what really makes people laugh,” an endeavor that encompassed developmental and behavioral psychology, neuroscience and theories of evolution.

“Laughter is part of this universal human vocabulary,” Dr. Provine once told NPR. “Everyone speaks this language. Just as birds of a given species all sing their species’ typical song, laughter is part of our own human song.”

He was drawn to the study of laughter, among other behavioral phenomena, in part because he had grown lonely in the laboratory, where he devoted the early years of his career to the study of nerve cells.

“I was getting tired of putting electrodes in nerve cells in a windowless room for six- or eight-hour days,” he told the Boston Globe in 2012. “But I was also interested in examining human behaviors using the same kind of rigorous procedures.”

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Those procedures, at first, included inviting study participants to sit in a lab and watch episodes of “Saturday Night Live” or bits by comedians Rodney Dangerfield, George Carlin and Joan Rivers. The setting proved unconducive to laughter, however, and forced Dr. Provine and his colleagues to change course.

In what he described as “the spirit of Jane Goodall heading out to Gombe Stream Preserve to study chimpanzees,” he set out on an “urban safari” to observe people laughing in shopping malls and on the street. On one occasion, he wrote, a “large and aggressive woman” mistook him for a store detective.

With help from assistant researchers, he observed 1,200 examples of laughter. The team decamped for the acoustic laboratory at the National Zoo in Washington, where they studied recordings of laughter on equipment designed to analyze bird calls. From this research, Dr. Provine drew a number of conclusions.

Most fundamental was the observation that laughter usually comes in response not to uproarious humor, but rather to dialogue that he compared to an “interminable television situation comedy scripted by an extremely ungifted writer.”

Some laughter might reward a knee-slapping joke, but he found that it serves more often to establish or strengthen bonds between a speaker and the person or people listening. Laughter can be used unkindly, too, to wound or to exclude someone from a group. In other situations, a person may laugh at jokes made by a superior to acknowledge that person’s authority.

Outside the confines of a comedy club, people who are speaking tend to laugh more than their interlocutors. Women, Dr. Provine found, laugh more at men than men laugh at women. Only when a man was speaking to a woman did the person listening laugh more than the person speaking.

He described laughter as an “honest social signal because it’s hard to fake.”

“We’re dealing with something powerful, ancient and crude,” he once told the New York Times. “It’s a kind of behavioral fossil showing the roots that all human beings, maybe all mammals, have in common.”

Dr. Provine’s book “Curious Behavior” examined other behaviors humans (and many animals) have in common, including crying, tearing up in emotion, sneezing and belching. His study of yawning revealed that all vertebrates, including fish, yawn; that yawns often come during moments of transition, not only when one falls asleep or wakes up, but also when one is cold and becomes warm; and, perhaps counterintuitively, that yawns can often accompany excitement. Paratroopers, he discovered, yawn before making a leap.

“With its many facts and anecdotes and unexpected stories, [the volume] begs you to continue where curiosity leads you, down both the boulevards and the back alleys of science,” reviewer James Gorman wrote in the National Post of Canada. “And that is exactly how he thinks science should be pursued. ‘You follow the trail wherever it goes,’ he said.”

Robert Raymond Provine was born in Tulsa on May 11, 1943. His father was a chemist, and his mother was a homemaker. As a high school student, Dr. Provine built telescopes, an endeavor that attracted coverage in local newspapers — his first foray into popular science.

He studied psychology at Oklahoma State University, where he received a bachelor’s degree in 1965, and at Washington University in St. Louis, where he received a PhD in 1971. His graduate school advisers included the embryologist Viktor Hamburger and Rita Levi-Montalcini, a Nobel Prize-winning neuroscientist

Dr. Provine’s first marriage, to Helene “Vivi” Vona, ended in divorce. Survivors include his wife of 23 years, Helen Weems of Columbia, Md.; two children from his first marriage, Kimberly Lourenco of Olney, Md., and Robert W. Provine of West Hollywood, Calif.; and three grandchildren.

A reporter for The Washington Post once asked Dr. Provine about the reaction he received from dinner party guests when he told them the subjects of his scientific inquiry.

“Everyone always seems interested,” he said. “Then they ask if I am observing them.”

If he wasn’t, he added, he “wouldn’t be a good scientist.”

“I think the only way to be successful, whether you are doing science or running a restaurant, is that you have to be totally engaged in what you’re doing,” Dr. Provine said. “You can’t turn it on and off.”