NEW YORK — Lewis Yablonsky carried a switchblade before he became a sociologist.
“My need for self-protection stemmed, in part, from my teenage years as a dice and card hustler,” Mr. Yablonsky wrote, recalling his days at South Side High School in Newark. “During this phase of my life I hung out with many individuals who I would, later on, after my formal education, characterize as sociopaths.”
He made good money cheating at cards and dice. He went on to make a remarkable career hanging out with and writing about sociopaths — gangsters, drug dealers, murderers — as well as more ordinary characters, such as unhappily married couples.
Mr. Yablonsky, who was 89 when he died on Jan. 29 in Santa Monica, Calif., became a prominent and provocative public intellectual in the 1960s, combining academic analysis, experiential research, and sometimes direct, unconventional efforts to solve social problems.
In the 1950s, he was still in graduate school when he started a youth athletic program to help battle juvenile crime in the troubled Morningside Heights neighborhood of Manhattan. To get gang members to participate in his studies, he sometimes paid them to fill out questionnaires. Soon, they were hanging out in his office, then his home. The work led to his first book, “The Violent Gang,” published in 1962.
“Most had no real concept of belonging to any gang or group,’’ Dr. Yablonsky told The Boston Globe, referring to participants in a rumble in Morningside Heights. “However, they were interested in a situation which might be exciting and possibly a channel for expressing some of their aggressions and hostilities.’’
He had been an associate professor at the University of Massachusetts Amherst and a lecturer at Harvard University in the late 1950s and early 1960s before moving to California.
Mr. Yablonsky emphasized street-level immersion over academic remove. He took LSD as part of his research for “The Hippie Trip,” his 1968 book about hippie culture. He drew on personal experience, particularly his sexually open marriage, for his 1979 book, “The Extra-Sex Factor: Why Over Half of America’s Married Men Play Around.”
“His wide-ranging work has improved organizational performance, made communities better, and elevated the field of sociology in the United States and abroad,” the American Sociological Association said in giving him a career achievement award in 2003.
Mr. Yablonsky often said his rough childhood had helped him see the complexity in people and inspired his belief in treatment over punishment. When he was a boy, in the 1930s, he recalled being beaten by whites who mocked his Jewishness and by blacks who mocked his whiteness. He rode along in his father’s laundry truck in tough neighborhoods, he said, in part to prevent people from stealing the truck. He often marveled that, unlike so many of the people he grew up with, he did not go to prison.
“My greatest achievement in life,” he liked to say, “was getting out of Newark.”
He received a baseball scholarship to the University of Alabama, but stayed only a year; he did not like Southern bigotry, he said, though he did win a lot of games of craps. Navy service in World War II gave him perspective, he said. He dropped the hustling, earned a bachelor’s degree at Rutgers, enrolled in graduate school at New York University, and earned his master’s in 1958.
When he was a college professor in California in the 1960s, he hosted family therapy sessions on public television, encouraging angry wives to speak their minds to adulterous or just obtuse husbands.
He taught at the University of California Los Angeles before moving to California State University Northridge in 1963. He spent more than 30 years there, but his favorite classrooms were usually off campus.
In 1961, he met Donna King while he was visiting Synanon, a rehabilitation center in Santa Monica where addicts were both patients and group therapists. Mr. Yablonsky was there as a researcher, King for treatment. She had been a drug addict since she was a teenager.
One of his best-known books, “The Tunnel Back: Synanon,” (published in 1965), was partly about his experience meeting and marrying her and his belief in the Synanon system. The marriage lasted 17 years, many of them tumultuous, before they divorced. (Synanon later lost credibility after declaring itself a religion and being linked to a series of violent episodes.)
Lewis Edward Yablonsky was born in Irvington, N.J., the second of three sons of Harry and Fannie Yablonsky.
Mr. Yablonsky leaves his son, Mitchell, who confirmed his death; and a brother, Joseph. His former wife, Donna, died in the late 1980s.