Calculating Behavior

Good Choice: R. Duncan Luce chose mathematical behavioral science as a career despite the uncertainty of its future at the time.

Luckily for science, as a child R. Duncan Luce had astigmatism and parents who didn’t think much of art as a career choice. Otherwise, he might have ended up a fighter pilot or an artist instead of a pioneer in mathematical behavioral science. As it is, during his career he has focused on constructing and testing mathematical models of the commonalities among people.

In a third-person biographical note written in 1989, Luce recalled his youth in Scranton, Pennsylvania. “Airplanes and painting consumed much time and attention but parental influence weighed strongly against an art career, for which both the world and he can be thankful, and astigmatism ruled out military flying.”

The future recipient of the National Science Medal started out with good genes as a member of a family of risk-takers. His father was first cousin to Time magazine founder Henry Luce, and he described a vague memory of meeting the publisher’s father during childhood. The elder Luce, who had been a missionary in China, “took out a big piece of heavy paper and drew a bunch of Chinese characters and explained what they were.”

Luce started his career in a field diametrically opposed to the behavioral sciences. The future APS Fellow, Charter Member, William James Fellow Award recipient, and Board Member (1989-1991) initially planned a career in aeronautical engineering, his undergraduate degree field. After graduating from Massachusetts Institute of Technology, Luce spent time in the Navy during World War II. Following the war, the Navy paid his way through an accelerated engineering program. Luce then completed midshipman school at Notre Dame, and Catapult and Arresting Gear School in Philadelphia, where he learned how to guide airplane launches and landings on aircraft carriers.

This was followed by the shake-down cruise on the carrier USS Kearsarge from Brooklyn to Guantanamo, Cuba. “I was essentially a passenger,” recalled Luce, because the Navy thought it wiser to entrust launches and landings to an experienced officer instead of “a very green ensign.”

After his discharge, Luce returned to MIT for graduate study in applied mathematics, but was unsure of his goal. He knew he didn’t want to do physical science applications or be a pure mathematician. “Economics was one possibility,” he said. “The other was psychology. I didn’t know very much about either.”

Through a room- mate, Luce met social psychologist Leon Festinger, who introduced him to Alex Bavelas, who in turn invited him to join his social networks laboratory after Luce received his PhD in 1950. Luce faced what he termed “a major career choice” — teaching in a math department with minor interest in behavioral science, or putting his math skills to use in behavioral sciences. He gambled on the latter and joined Bavelas’ lab.

That choice, he said, started an “uneasy nine years.” Mathematical behavioral science was still in its infancy. “There were pockets of it, but it wasn’t a strong discipline. It wasn’t obvious this was going to work. It was well within possibility that I wasn’t going to be able to do anything. I didn’t know how good I might be. It’s hard to be very self-confident at that age.” He was 25.

Much of the early work in mathematical behavioral science grew out of wartime interdisciplinary collaborations, and much of that went on in Cambridge, Massachusetts, including applications for information theory, cybernetics, and social networks. “It was,” Luce recalled, “a very, very lively place.”

At the lab he received a “fine informal education in weekly seminars,” learning from the likes of Noam Chomsky, William McGill, George Miller, and Walter Rosenblith. From there he went on to Columbia University as managing director of a behavioral models project, then to a year at Stanford University’s Center for Advanced Study in the Behavioral Sciences, followed by Harvard, then the University of Pennsylvania, where he participated in the rebirth of its psychology department. As he later wrote, “The 1950 bet had paid off.”

Although he has never taken a course in either psychology or statistics, Luce is now recognized as a leading theoretician in mathematical psychology. Dean Barbara Dosher of the University of California, Irvine, School of Social Sciences called him “one of the giants of the social and behavioral sciences … [whose] work has fundamentally altered our understanding of how individuals and groups make decisions.”

President Bush awards the 2003 National Medal of Science in the field of behavioral and social sciences to former APS Board Member R. Duncan Luce, University of California at Irvine, during a ceremony in the White House on March 14, 2005. The award is the highest national honor for scientists.

Luce received national recognition for his achievements earlier this year when he was awarded the National Medal of Science — widely considered the highest national honor for scientists — for his work in the field of behavioral and social sciences. President Bush presented the medal at a White House ceremony on March 14, 2005.

Luce recalled the scene: In the Blue Room, the president went down the line of scientists, shaking hands with each, then said a few words and left. “We were marched into the East Room and sat down, he came in and read a little speech, then called our names and read the citation.” As each scientist went up, he hung the medal around his or her neck and said a few personal words. “In my case, he noticed I was wearing a rather interesting Navajo [belt] buckle. Most of the others had the good sense to have their suit coats buttoned. I had forgotten to do that.” Then the president left and they were treated to a buffet lunch.

Among Luce’s nine books, Individual Choice Behavior is widely recognized as groundbreaking, but perhaps the most challenging to write was Volume I of Foundations of Measurement. That volume was written during a tumultuous sabbatical year in Rio de Janeiro, Brazil, where he was teaching statistics at Pontifical Catholic University.

“There was a great deal of unrest on the campus, stemming from the military takeover that year [1967]. More than once I was phoned in the morning and told to stay home until further notice” Luce recalled. Once he found school walls riddled by machine-gun fire. “I also encountered military road blocks when commuting. This was especially scary because of my pathetic lack of linguistic skills. I learned embarrassingly little Portuguese.”

Brazil was followed by Princeton’s Institute for Advanced Study; then the University of California, Irvine; then a return to Harvard, and ultimately back to UCI in 1988 as Distinguished Professor of Cognitive Science and director of the Institute for Mathematical Behavioral Sciences. He retired from teaching in 1996 and as institute director in 1998.

Since “retiring” Luce has been applying the basic ideas he developed to individual decision-making.

His current interest, he says, is gambling — building and testing in computer-based lab experiments models to predict how people approach decisions that involve risk. “I’ve been able to get pretty interesting results that go beyond what other people have gotten,” he said.

“I’m fully prepared to accept that I may be wrong. We do experiments on these assumptions, but in social sciences we don’t have anywhere like the precision that you can get in physics. There’s always indecision. You can try to reduce the uncertainty, but a lot of it seems irreducible. Maybe some clever person will come along and improve [on his models], but we’re certainly a lot better today than a century ago.”

The potential relevance of his current research seems limitless. “Almost everything we do in life is a gamble,” Luce said, citing not only games of chance, but driving, flying, investing, anything that involves uncertainty. Like his career decision more than 50 years ago.

Now 80 and still pushing the envelope, he has a simple prescription for a long healthy life: “A balanced diet, a lively intellectual life, and by all means avoid strenuous exercise. And I almost forgot — inherit good genes.”