Alice Kahn Ladas, a psychologist and psychotherapist who helped loosen constraints on women’s sexual experience as a co-author of the best-selling book “The G Spot: And Other Recent Discoveries About Human Sexuality,” died July 29 at her home in Santa Fe, New Mexico. She was 102.

Her daughter Robin Janis confirmed her death and said she did not know the cause.

Published in 1982, “The G Spot” took book clubs by storm on its way to selling more than 1 million copies around the world. It remains in print, an enduring entry in the canon of books that emerged in the wake of the sexual revolution and the women’s liberation movement.

Dr. Ladas wrote “The G Spot” with two colleagues – Beverly Whipple, a nurse and researcher in human sexuality, and John D. Perry, an ordained minister, psychologist and sexologist.

With their work, they followed in the tradition established by researchers including Alfred C. Kinsey in the 1940s and 1950s, William H. Masters and Virginia E. Johnson in the 1960s and Shere Hite in the 1970s, who had ignored taboos surrounding sex to examine the topic frankly and scientifically.

Dr. Ladas was particularly concerned with female sexual pleasure, once telling an interviewer that she “was always interested in women being able to own their own bodies and use their bodies the way they wanted.”

She and her co-authors ranked the erogenous zone known as the “G spot” and its associated orgasms as the most important topic addressed in their book.

The G spot owes its name to the German physician Ernst Gräfenberg, who described it in the mid-20th century and placed the zone within the front wall of the vagina, just behind the pubic bone.

“The G spot is what specifically frees us from the either/or thinking of the past decades, for it demonstrates that there is not one genital focus of erotic arousal in women,” Dr. Ladas and her co-authors wrote. “There are, instead, at least two foci – the clitoris and the G spot.”

Dr. Ladas credited the research in the book to her co-authors, telling the Santa Fe Reporter that her role “was to see the connection – there was a vaginal orgasm, there was a clitoral orgasm, but they’re not exclusive.” The writers reported that they examined 400 women ranging in age from 20 to 78 and that all were determined to have a G spot.

But the existence of the G spot had long been debated and remained a topic of contention after the publication of Dr. Ladas’s book.

A reviewer for The Washington Post, Elizabeth Hess, wrote that “instead of defending (their) astounding revelation with hardcore, scientific data,” Dr. Ladas and her co-authors “choose an inordinate number of soft-core testimonials (including one from a trainer of seeing-eye dogs) from women with born-again sex lives, who believe in their spots.”

In another news article on the book, Robert Francoeur, a professor of human sexuality, told the New York Times that the “professional jealousy … is incredible.”

“The nasty comments from professionals sound like they’re upset that they didn’t write the book,” he added.

A 2021 article in the journal Sexual Medicine surveyed 31 studies in medical literature examining the G spot. “The different studies did systematically agree on the existence of the G-spot,” the authors concluded. But “among the studies in which it was considered to exist, there was no agreement on its location, size, or nature. The existence of this structure remains unproved.”

In “The G Spot,” Dr. Ladas and her co-authors also addressed the role of healthy pelvic muscles in sexual experience as well as topics including female ejaculation, which not all but some women report experiencing.

“All of us are very different, and that’s okay,” Dr. Ladas once remarked. “You don’t have to be like anybody else.”

Alice Rosalie Kahn was born in New York City on May 30, 1921. Her mother was a member of the humanist Ethical Culture movement and enrolled her daughter in the Ethical Culture Fieldston School in Manhattan, where Alice graduated in 1939.

Her parents were divorced, and she spent summers in Alabama with her father, a cotton merchant. Her observations of the indignities African Americans endured in the Jim Crow South inspired her involvement in the civil rights movement, her daughter said.

Dr. Ladas studied at Smith College, where she received a bachelor’s degree in political science in 1943 and a master’s degree in social service in 1946. She became intrigued by the work of Wilhelm Reich, an Austrian-born psychoanalyst who generated controversy with his theories about sexual energy, and worked for a period with him as an assistant.

Dr. Ladas devoted herself throughout her career to the connection between mind and body, including as an early instructor in Lamaze, a childbirth technique centered on relaxation and breathing.

In the early 1970s, she received a doctorate in education from Columbia University Teachers College. For her dissertation, she worked with La Leche League to examine the importance of information and support to breastfeeding mothers.

The dissertation proposal was initially rejected, according to a profile of Dr. Ladas published by Smith College, until anthropologist Margaret Mead joined the reviewing committee and endorsed its value.

Dr. Ladas was married in 1963 to Harold S. Ladas, a professor of psychology at Hunter College in New York City and a collaborator on “The G Spot.” The authors dedicated their book to Harold Ladas, “our silent partner.”

Dr. Ladas never retired. According to her daughter, she saw three patients the afternoon before she died and had remarked that she was doing “the best work of her life.”

A complete list of survivors was not immediately available.

For all of her work to document the existence and importance of the G spot, Dr. Ladas told the Santa Fe Reporter that “this whole business of ‘you have to find the G-spot’ is silly.”

“Being able to communicate, to enjoy your body,” she continued, “that’s important.”