Mead earned her bachelor’s degree from Barnard in 1923, then began studying with professor Franz Boas and Ruth Benedict at Columbia University, earning her master’s degree in 1924. Mead set out in 1925 to do fieldwork in Samoa. In 1926, she joined the American Museum of Natural History, New York City, as assistant curator. She received her PhD from Columbia University in 1929.

In 1926, there was much debate about race and intelligence. Mead felt the methodologies involved in the experimental psychology research supporting arguments of racial superiority in intelligence were substantially flawed. In “The Methodology of Racial Testing: Its Significance for Sociology” Mead proposes that there are three problems with testing for racial differences in intelligence. First, there are concerns with the ability to validly equate one’s test score with what Mead refers to as racial admixture or how much Negro or Indian blood an individual possesses. She also considers whether this information is relevant when interpreting IQ scores. Mead remarks that a genealogical method could be considered valid if it could be “subjected to extensive verification”. In addition, the experiment would need a steady control group to establish whether racial admixture was actually affecting intelligence scores. Next, Mead argues that it is difficult to measure the effect that social status has on the results of a person’s intelligence test. By this she meant that environment (i.e., family structure, socioeconomic status, exposure to language) has too much influence on an individual to attribute inferior scores solely to a physical characteristic such as race. Lastly, Mead adds that language barriers sometimes create the biggest problem of all. Similarly, Stephen J. Gould finds three main problems with intelligence testing, in his 1981 book The Mismeasure of Man, that relate to Mead’s view of the problem of determining whether there are racial differences in intelligence.

Mead was married three times. After a six-year engagement, she married her first husband (1923–1928) American Luther Cressman, a theology student at the time who eventually became an anthropologist. Between 1925 and 1926 she was in Samoa returning wherefrom on the boat she met Reo Fortune, a New Zealander headed to Cambridge, England, to study psychology. They were married in 1928, after Mead’s divorce from Cressman. Mead dismissively characterized her union with her first husband as “my student marriage” in her 1972 autobiography Blackberry Winter, a sobriquet with which Cressman took vigorous issue. Mead’s third and longest-lasting marriage (1936–1950) was to the British anthropologist Gregory Bateson, with whom she had a daughter, Mary Catherine Bateson, who would also become an anthropologist.

In 1929 Mead and Fortune visited Manus, now the northernmost province of Papua New Guinea, travelling there by boat from Rabaul. She amply describes her stay there in her autobiography and it is mentioned in her 1984 biography by Jane Howard. On Manus she studied the Manus people of the south coast village of Peri. “Over the next five decades Mead would come back oftener to Peri than to any other field site of her career.

During World War II, Mead was executive secretary of the National Research Council’s Committee on Food Habits. She was curator of ethnology at the American Museum of Natural History from 1946 to 1969. She was elected a Fellow of the American Academy of Arts and Sciences in 1948. She taught at The New School and Columbia University, where she was an adjunct professor from 1954 to 1978 and was a professor of anthropology and chair of the Division of Social Sciences at Fordham University’s Lincoln Center campus from 1968 to 1970, founding their anthropology department. In 1970, she joined the faculty of the University of Rhode Island as a Distinguished Professor of Sociology and Anthropology.

Following Ruth Benedict’s example, Mead focused her research on problems of child rearing, personality, and culture. She served as president of the Society for Applied Anthropology in 1950 and of the American Anthropological Association in 1960. In the mid-1960s, Mead joined forces with communications theorist Rudolf Modley, jointly establishing an organization called Glyphs Inc., whose goal was to create a universal graphic symbol language to be understood by any members of culture, no matter how “primitive”. In the 1960s, Mead served as the Vice President of the New York Academy of Sciences. She held various positions in the American Association for the Advancement of Science, notably president in 1975 and chair of the executive committee of the board of directors in 1976. She was a recognizable figure in academia, usually wearing a distinctive cape and carrying a walking-stick.

Mead was featured on two record albums published by Folkways Records. The first, released in 1959, An Interview With Margaret Mead, explored the topics of morals and anthropology. In 1971, she was included in a compilation of talks by prominent women, But the Women Rose, Vol.2: Voices of Women in American History.

In the 1967 musical Hair, her name is given to a tranvestite ‘tourist’ disturbing the show with the song ‘My Conviction’.

In 1976, Mead was a key participant at UN Habitat I, the first UN forum on human settlements.

In 1976, Mead was inducted into the National Women’s Hall of Fame.

She spent her last years in a close personal and professional collaboration with anthropologist Rhoda Metraux, with whom she lived from 1955 until her death in 1978. Letters between the two published in 2006 with the permission of Mead’s daughter clearly express a romantic relationship.

Mead died of pancreatic cancer on November 15, 1978, and is buried at Trinity Episcopal Church Cemetery, Buckingham, Pennsylvania.

On January 19, 1979, President Jimmy Carter announced that he was awarding the Presidential Medal of Freedom posthumously to Mead. UN Ambassador Andrew Young presented the award to Mead’s daughter at a special program honoring Mead’s contributions, sponsored by the American Museum of Natural History, where she spent many years of her career. The citation read:

In 1979, the Supersisters trading card set was produced and distributed; one of the cards featured Mead’s name and picture.

In 1983, five years after Mead had died, New Zealand anthropologist Derek Freeman published Margaret Mead and Samoa: The Making and Unmaking of an Anthropological Myth, in which he challenged Mead’s major findings about sexuality in Samoan society. Freeman’s book was controversial in its turn: later in 1983 a special session of Mead’s supporters in the American Anthropological Association (to which Freeman was not invited) declared it to be “poorly written, unscientific, irresponsible and misleading.”

In 1996, author Martin Orans examined Mead’s notes preserved at the Library of Congress, and credits her for leaving all of her recorded data available to the general public. Orans point out that Freeman’s basic criticisms, that Mead was duped by ceremonial virgin Fa’apua’a Fa’amu (who later swore to Freeman that she had played a joke on Mead) were equivocal for several reasons: first, Mead was well aware of the forms and frequency of Samoan joking; second, she provided a careful account of the sexual restrictions on ceremonial virgins that corresponds to Fa’apua’a Fa’auma’a’s account to Freeman, and third, that Mead’s notes make clear that she had reached her conclusions about Samoan sexuality before meeting Fa’apua’a Fa’amu. Orans points out that Mead’s data support several different conclusions, and that Mead’s conclusions hinge on an interpretive, rather than positivist, approach to culture. Orans goes on to point out, concerning Mead’s work elsewhere, that her own notes do not support her published conclusive claims. However, there are still those who claim Mead was hoaxed, including Peter Singer and zoologist David Attenborough. Evaluating Mead’s work in Samoa from a positivist stance, Martin Orans’ assessment of the controversy was that Mead did not formulate her research agenda in scientific terms, and that “her work may properly be damned with the harshest scientific criticism of all, that it is ‘not even wrong’.”

The USPS issued a stamp of face value 32¢ on May 28, 1998, as part of the Celebrate the Century stamp sheet series.

In 1999, Freeman published another book, The Fateful Hoaxing of Margaret Mead: A Historical Analysis of Her Samoan Research, including previously unavailable material. In his obituary in The New York Times, John Shaw stated that his thesis, though upsetting many, had by the time of his death generally gained widespread acceptance. Recent work has nonetheless challenged his critique. A frequent criticism of Freeman is that he regularly misrepresented Mead’s research and views. In a 2009 evaluation of the debate, anthropologist Paul Shankman concluded that:

The 2014 novel Euphoria by Lily King is a fictionalized account of Mead’s love/marital relationships with fellow anthropologists Reo Fortune and Gregory Bateson in pre-WWII New Guinea.

In her 2015 book Galileo’s Middle Finger, Alice Dreger argues that Freeman’s accusations were unfounded and misleading. A detailed review of the controversy by Paul Shankman, published by the University of Wisconsin Press in 2009, supports the contention that Mead’s research was essentially correct, and concludes that Freeman cherry-picked his data and misrepresented both Mead and Samoan culture.