A pioneering network-science scholar whose work reshaped the scientific understanding of the dynamics of social influence will give a talk Sept. 13, sharing insights gained over 20 years of research into the field he helped create.

The upcoming campus visit of Duncan Watts, Ph.D. ’97, will be the last of his six-year term as an Andrew Dickson White Professor-at-Large. His public talk, “From Small World Networks to Computational Social Science: Two Decades of Research in Between Disciplines,” will be held at 4:30 p.m. in G10 Biotech.

The talk comes 20 years after Watts helped launch the field of network science with the pivotal paper, “Collective Dynamics of Small-World Networks,” co-authored with Steven Strogatz, the Jacob Gould Schurman Professor of Applied Mathematics. Since then, Watts has served as a professor of sociology at Columbia University and the director of the Human Social Dynamics Group at Yahoo Research. He’s currently a principal researcher and founding member of the Microsoft Research Lab in Manhattan.

His talk will offer “an interdisciplinary sense of what network science has been about for the last 20 years,” said Strogatz, who was Watts’ academic adviser and is now his host at Cornell, along with Michael Macy, the Goldwin Smith Professor of Arts and Sciences. “It goes from social sciences sparking the question and then being addressed by physics and math, with implications for biology. It’s kind of a beautiful story, very suitable for an A.D. White talk in that it spans all these different subjects that very organically and naturally help each other.”

Network science is an interdisciplinary field that uses the tools of sociology, math, physics, statistics and computer and information science to explore interconnected systems.

Studying the synchronization of snowy tree crickets, who chirp in unison in vast choruses, led Watts and Strogatz to the 1998 paper that explained the concept of six degrees of separation and made a “really fundamental breakthrough that changed our understanding of how diffusion occurs on networks, and how contagion spreads,” said Macy, who is also director of Cornell’s Social Dynamics Laboratory. Watts’ research, challenging conventional thinking on influence, has had implications for the spread of ideas, technical innovations and disease, he added.

As a professor-at-large, Watts has been particularly involved with the class Six Pretty Good Books: Explorations in Social Science, which often begins with Watts’ 2011 book, “Everything is Obvious (Once You Know the Answer).”

“We start with Duncan’s book because it arms students with the analytical tools to critically assess the validity of common-sense explanations for human behaviors,” Macy said.

During his upcoming visit, Watts will speak to the class and help design a lab experiment at Cornell based on his own influential music study, in which he examined music downloads to reveal unpredictable patterns in popularity. He will also give a math-focused talk at the Center for Applied Math Colloquium Sept. 12 at 4:15 p.m. in 255 Olin Hall.

The Sept. 13 talk, which will be aimed at a broad audience, will trace the history of computational social science, in addition to discussing the impact of his own research and how his thinking has evolved over time, Macy said.

“Certainly Duncan’s work is directly relevant to today’s political environment, with echo chambers and political polarization and the sharp divide between right and left,” he said. “He’s very good at taking complex ideas that are at the forefront of the science of networks and making those accessible, so I think people will find the lecture engaging and important.”

Cornell will host seven visits from its 17 active professors-at-large this academic year. Evolutionary biologist David Hillis, linguist John Rickford and artist Xu Bing will also be visiting campus in September.