This article is part of Overlooked, a series of obituaries about notable people whose deaths, beginning in 1851, went unreported in The Times.
Unlike most of the 120,000 Japanese Americans held in internment camps across the United States during World War II, James Sakoda had a mission: to document the experience of incarceration. He took about 1,800 pages of notes, mostly private, to avoid being accused of being a traitor or a spy.
Those notes would form the basis of his 1949 dissertation on the dynamics of individuals and groups in one of these camps, the Minidoka War Relocation Center in Idaho. Appendix B of the paper contained possibly the first example of what is known as an “agent-based model” – a simulation of how individual actions can add up to large-scale patterns.
The tool is essential in a wide variety of fields and has helped social scientists, epidemiologists, financial regulators, urban planners and wildlife experts in their work. For example, during the coronavirus pandemic, agent-based models were essential for predicting the spread of the virus and prioritizing vaccines for certain groups of people.
To develop the model, Sakoda used the home computer technology of the time: a checkerboard. Each disc was given a simple move rule based on its immediate environment. By changing the rules even slightly, Sakoda showed that the pieces could mix freely, or they could quickly separate by color.
Ecologists and environmentalists have used agent-based models to study the interactions between shipping boats and beluga whales in the mouth of Canada’s St. Lawrence River; between people and elephants in Tanzania; and between diving tourism and coral reefs in Thailand. Transport agencies use the models to predict how even small changes, such as expanding a bus stopcan affect the flow of traffic.
“James Sakoda may have been the first ever social scientist to apply computational modeling to unravel the complexities of social processes,” Andreas Flache, a sociologist at the University of Groningen in the Netherlands, said in an email.
Despite the widespread use of his model, Sakoda did not receive much praise for his innovation.
James Minoru Sakoda, known as Jimmy, was born on April 21, 1916, on an alfalfa farm in Lancaster, California, northern Los Angeles County. His conservative Buddhist parents, Kenichi and Tazu (Kihara) Sakoda, were both from Japan.
After moving around the Los Angeles area, his parents took their four children to Japan, where James attended high school for three years and Tokyo University for another three years.
With $100 in his pocket, Sakoda returned to California and enrolled at the University of California, Berkeley, where he studied psychology. During his second year there, the Secretary of War established detention camps for Americans of Japanese descent on the West Coast.
Sakoda was still at Berkeley when he began documenting the responses of Japanese-Americans to the crisis. Through a classmate, he met Dorothy Swaine Thomas, a sociologist who was soon recruiting field workers for a project called the Japanese American Evacuation and Resettlement Study.
All four Sakoda siblings were back in the United States by the time they were sent to one of these camps; their parents remained in Japan during the war. Sakoda, his brother, George, and his sisters, Ruby and May, were initially incarcerated in 1942 at the Tulare Assembly Center in central California’s San Joaquin Valley.
“Soldiers stood watching with rifles and Tommy guns,” Sakoda wrote in his diary, noting that tall grass was sticking through the asphalt floors of his barracks and the condition of the latrines was “open to criticism”.
He went on to describe day-to-day camp life for Thomas’s project, always in a detached, analytical way. “I never talked about this happening to us,” he said told the historian Art Hansen in 1988. Instead, he said, he viewed it as, “It happened to them.”
The study “gave him a sense of purpose,” Hansen said in a phone interview. “He kind of played a saving role for not just his community, but for American history in general.”
The Sakoda siblings were later transferred to the Tule Lake Relocation Center, near California’s northern border, where James taught psychology to inmates and met his future wife, Hatsuye Kurose, who was known as Hattie—the “smartest girl in my life.” class,” he said. called her in a letter to Thomas.
James and Hattie then spent two years at the Minidoka camp in Idaho, where they married before returning to Berkeley shortly before the camp closed in 1945.
Sakoda was working on a Ph.D. in psychology from Berkeley when a fellowship took him to Harvard. There he developed his checkerboard model, investigating the interactions between different groups in the internment camps: the ‘clanish’ Nisei; children of Japanese immigrants; more withdrawn prisoners; and camp administrators.
After receiving his doctorate from Berkeley in 1949, he briefly taught at Brooklyn College before joining the Psychology Department at the University of Connecticut. There he developed an interest in the potential of computers in studying human behavior.
In the summer of 1956, Sakoda learned to program on early IBM punched card computers at MIT. a computer lab for social sciences.
At a time when the study of human behavior was largely isolated from computers, Sakoda pushed for better tools to merge the two; the checkerboard model, which he taught students over the next three decades, was just one of them.
In 1963 he was invited to a summer institute at the RAND Corporation in Santa Monica, California, to exchange ideas on modeling cognitive processes using computers. While there, he began developing his own social scientist computing toolbox, which he called DYSTAL. A 1971 paper, “The Checkerboard Model of Social Interaction,” modernized his 1949 model through computer-aided simulations.
After retiring from Brown in 1981, Sakoda told Hansen, “I think the best thing I’ve done is the social interaction model, which solved the problem in social psychology of moving from the individual level to the group level.”
But in the 1990s and 2000s, when agent-based modeling became fundamental to the large-scale study of infectious diseases and human movements, another origin story emerged.
Thomas Schelling, a well-connected Harvard economist and White House adviser, was on a plane bound for Boston when he started messing around with Xs and Os running along a line. It would eventually become a checkerboard model remarkably similar to Sakoda’s. Schelling mentioned it in a 1969 RAND investigative report and expanded it into an article in 1971, shortly after Sakoda published his own, in the same journal.
Decades later, it was Schelling’s paper that is widely credited as the first in which the checkerboard model appeared.
It’s possible that Schelling stumbled upon the germ of the idea at RAND – he completed a residency there a year after Sakoda visited him. But when asked in a 2001 interview if Sakoda’s checkerboard model had influenced him, Schelling replied, “I’ve never heard of him.”
Schelling was awarded the Nobel Prize in Economics in 2005 Robert J. Aumann, for “advanced our understanding of conflict and cooperation through game theory analysis.” In a biographical statement accompanying the award, Schelling wrote of the checkerboard model: “Unknowingly, I pioneered a field of study that later became known as agent-based computational modeling.”
In his later years, in Barrington, RI, Sakoda focused on gardening, his family, and a longstanding math sideline: origami. His book “Modern Origami”, published in 1969 and still in print, shows his own designs and made him notable among enthusiasts. (He decorated his computer lab in Brown with his origami.)
His cousin Jim Kurose said in an interview that at family gatherings, Sakoda “usually sat quietly alone in the living room and pulled out his paper, and he started folding, and he just kept kids totally enthralled.”
He died on June 12, 2005. He was 89.
Sakoda’s agent-based modeling innovations are being rediscovered thanks to the research of Rainer Hegselmann, a philosopher and social scientist at the Frankfurt School of Finance and Management in Germany. In a Article from 2017 in the Journal of Artificial Societies and Social Simulation, Hegselmann speculated that the timing of Sakoda’s retirement, in 1981, before the personal computer became ubiquitous, may have led to his achievement being erased.
“Perhaps that life punishes those who are late,” he wrote. “But sometimes it also punishes those who are too early.”
However, Sakoda “wasn’t very concerned about getting explicit credit for what he did,” his son, Bill, a computer scientist, said in an interview.
Instead, he added in an email, “He was very quietly working magic for a lot of people.”