Alison Jolly, an American-born primatologist whose research in the forests of Madagascar shed new light on the evolution of social intelligence and helped disprove a longstanding scientific tenet that males were dominant in every primate species, died on Feb. 6 in Lewes, East Sussex, England. She was 76.
The cause was breast cancer, said Barbara Orlando, a longtime friend.
Dr. Jolly’s two major insights emerged from her 1960s field studies of the lemur, a primate whose development in relative isolation on the island of Madagascar makes the species something akin to a living fossil.
Writing in the journal Science in 1966, Dr. Jolly cited lemurs’ complex social relationships as evidence of an unexplored trail in one of anthropology’s great mysteries: the evolution of higher intelligence. She suggested that the many hours lemurs spent in play, mutual grooming and networking — activities that establish social ties and hierarchies — may have been as important to the evolution of intelligence as the development of weapons and tools, then considered the hallmark of evolutionary advance.
More unnerving to colleagues was her discovery that in some primate species, females run the show. The finding upended a bedrock assertion in evolutionary biology, based on studies of chimpanzees and orangutans in captivity, that males dominated females in every primate species, including humans.
“Females have social, spatial and feeding priority over males,” Dr. Jolly wrote in describing the feeding, mating, child-rearing and recreational habits of the ring-tailed lemur, one of about 100 recognized species of lemur, of which more than a dozen are female-dominant. Among the ring-tailed lemurs, Dr. Jolly wrote in “Lemur Behavior: A Madagascar Field Study,” “all females, whether dominant or subordinate in the female hierarchy, are dominant over males.”
The most subordinate females would “at times pounce upon a dominant male and snatch a tamarind pod from his hand, cuffing him over the ear in the process,” she added.
Dr. Jolly’s findings were eventually accepted, though not without resistance, said Patricia C. Wright, a primatologist, lemur expert and professor of anthropology at Stony Brook University on Long Island.
“This was a real surprise to people in the ’60s,” Dr. Wright said. “Female leaders were still so rare. And here comes a woman presenting a model of primates where the females are leaders — effective leaders.”
Dr. Jolly, who wrote a half-dozen books and over a hundred papers while teaching and raising four children, variously did her research under the aegis of the New York Zoological Society, now called the Wildlife Conservation Society, Rockefeller and Princeton Universities and the Universities of Cambridge and Sussex in England. She was considered rare among figures of her prominence in never having sought a tenured university post. At her death she was a visiting scientist at Sussex.
Colleagues described Dr. Jolly as a quiet path maker. She received less attention than contemporaries like the primatologist Jane Goodall, even though she helped change the field and pioneered a brand of environmental activism that has helped preserve vast, fecund sections of Madagascar.
Dr. Jolly persuaded Madagascar’s frequently unstable governments to expand wilderness preserves that are home to lemurs and thousands of other species of animals and plants found nowhere else. She later wrote a series of children’s books in hopes of raising environmental awareness among the country’s young. The books chronicle the adventures of Ako, Tik Tik and Bitika, lemurs that confront daily environmental threats.
The naturalist David Attenborough, who featured her in his natural history programs for the BBC, said of Dr. Jolly in a recent tribute, “Not only lemurs, but the people and land of Madagascar captured her heart.”
Born Alison Bishop in Ithaca, N.Y., on May 9, 1937, she grew up in a household of literary and artistic accomplishment. Her mother, Alison Mason Kingsbury, was a noted portrait and landscape artist. Her father, Morris G. Bishop, a professor of romance languages at Cornell, was a novelist, essayist and comic poet who helped bring a friend, the Russian émigré Vladimir Nabokov, to Cornell as a literature professor.
Dr. Jolly received her bachelor’s degree from Cornell in 1958 and her Ph.D. in zoology from Yale in 1962. She made several extended trips to Madagascar for the field studies that informed her writings, including her books “The Evolution of Primate Behavior” (1972), “A World Like Our Own: Man and Nature in Madagascar” (1980) and “Lucy’s Legacy: Sex and Intelligence in Human Evolution” (1999).
Her survivors include her husband, Richard Jolly, a British economist; four children, Margaretta, Susan, Arthur and Richard Jr.; and four grandchildren.
In 2006, a new species of mouse lemur, the tiny Microcebus jollyae, was named in her honor.
In “A World Like Our Own,” Dr. Jolly described the allure of lemurs and their Texas-size habitat off the southeast coast of Africa. Lemurs provided “a clue to the moment when our own ancestors began to specialize in sociability,” she wrote. And Madagascar, she added, offered a chance to see “which rules would still hold true if time had once broken its banks and flowed to the present down a different channel.”