Daniel Yankelovich (Erik Jepsen/UC San Diego Publications)

Daniel Yankelovich, a pollster and author who spent decades charting emerging trends among the public and whose insights helped shape corporate marketing decisions and government policy, died Sept. 22 at his home in San Diego. He was 92.

His death was confirmed by the University of California at San Diego, which established a social science research institute in his name. The cause was reportedly kidney failure.

Public polling had been around long before Mr. Yankelovich entered the field in the 1950s, but he brought a special emphasis on psychology and sociology that sought to bring a human dimension to his findings.

After founding his first polling company in 1958, Mr. Yankelovich (pronounced yankle-OH-vitch), focused primarily on business and advertising rather than on that political polling for which some of his counterparts, including Louis Harris and George Gallup, were famous.

Mr. Yankelovich sought to gauge how the postwar American public would respond to imported products and to advertising campaigns, particularly on television. He helped popularize the term “baby boomers” to define a new and distinct youth market in the 1960s.

By the early 1970s, many leading companies were among his clients, including Dow Chemical, Volkswagen, General Electric, AT&T, Procter & Gamble and IBM. Mr. Yankelovich also formed a partnership with the New York Times to conduct polling in politics and other issues.

In 1975, he established the Public Agenda Foundation with Cyrus R. Vance, in an effort to put public officials in touch with ordinary citizens in determining public policy. Vance later became secretary of state under President Jimmy Carter, helping Mr. Yankelovich gain influence in the White House.

During the administration of President Bill Clinton, Mr. Yankelovich was described by Washington Post columnist Jim Hoagland in 1993 as “no mere analyst of opinion polls and national attitudes. He has become an important behind-the-scenes force shaping both action and reflection by the Clinton administration. His work has become must reading in the upper reaches of the White House, the State Department and elsewhere in government.”

Among the issues Mr. Yankelovich worked on with the Clinton administration were proposals to broaden health-care coverage and to “reinvent” government — both of which ultimately failed to gain support from an unreceptive Republican Congress.

Beginning in the 1960s, Mr. Yankelovich was among the first researchers to identify the changing views of young people as symbolic of a seismic cultural shift. His findings were used by Fortune magazine and CBS News in special reports about the generation gap. His 1972 book, “Changing Values on Campus,” described how the attitudes of young people had diverged from those of their parents.

In a later study of the youth culture, “The New Morality” (1974), Mr. Yankelovich concluded that the liberal idealism of the 1960s was already being replaced by a growing conservatism — and that women’s rights were supplanting other forms of political activism.

By 1979, a year before the election of Republican Ronald Reagan as president, Mr. Yankelovich’s opinion surveys were telling him that a profound mood change had swept the country.

The number of people struggling to pay for housing had doubled and, for the first time in decades, a majority of Americans believed the future would be grimmer than the past.

“We’ve gone almost overnight from a nation of optimists to a nation of pessimists,” Mr. Yankelovich said. His 1981 book, “New Rules: Searching for Self-Fulfillment in a World Turned Upside Down,” charted a shift away from America’s long-held belief in social and economic progress toward a growing rejection of tradition, self-denial and common purpose.

Mr. Yankelovich’s crystal ball was not always infallible, however. During the 1984 presidential campaign, he concluded that Reagan’s early lead in the polls was “very soft” and that young voters could sway the election toward a Democrat.

Reagan received almost 59 percent of the popular vote and won 49 states out of 50.

Daniel Yankelovich was born Dec. 29, 1924, in Boston. His mother died when he was young. His father painted houses after losing his job as a real estate agent during the Depression.

Mr. Yankelovich interrupted his studies at Harvard University to serve in the Army during World War II. After the war, he studied philosophy and psychology at Harvard, receiving a bachelor’s degree in 1948 and a master’s degree in 1950. He spent two years studying at the Sorbonne in Paris before beginning his career in market research.

His first marriage, to Hasmieg Kaboolian, ended in divorce. His second wife, Mary Komarnicki, died in a car accident in 1995. He was separated from his third wife, Barbara Lee. Survivors include a daughter from his first marriage; a sister; and a granddaughter.

Mr. Yankelovich taught at several colleges, including Tufts University in Massachusetts, New York University and the New School in New York.

In recent years, he lived in San Diego and donated millions of dollars to the University of California at San Diego.

“Opinion polls just measure people’s unresolved, half-baked feelings and views,” he said last year, when the university announced a bequest from Mr. Yankelovich. “The challenge is to help the public think through, deliberate, dissolve their own conflicts and finally reach considered judgment. From my view as a student of public opinion, converting raw opinion into considered judgment is indispensable to the efficient functioning of public democracy.”