Barbara Finlay, Evolutionary Neuroscience's 'Maverick,' Remembered for Rethinking How Brains Grow

In 1995, Barbara Finlay put forward a rule meant to describe the structure of every mammalian brain: each region scales with the overall size of the brain, and the moment a region starts to develop determines how large it becomes. Finlay died on 12 September at the age of 75, and the idea is the one she is most remembered for.

The view she was pushing against held that brain structure mirrors a species' functional adaptations. A large visual cortex meant sharp vision; a small auditory cortex meant poor hearing. Finlay argued that evolution could not sculpt brains so freely, because it had to work within the rigid rules of development. She drew on her knowledge of those rules and collected published data from 131 species. The resulting paper, written with her colleague Richard Darlington and published in Science, showed that brain structures scale together along different growth curves. Structures that begin later in development end up larger than those that begin earlier, because a bigger pool of progenitor cells is available to build them. The pair used the rule to predict when neurogenesis begins in different brain regions across many mammals.

Colleagues describe that sweep as characteristic. Gaby Maimon, who heads the Laboratory of Integrative Brain Function at Rockefeller University and was once an undergraduate researcher in her lab, said she gathered vast amounts of literature into new concepts. Alexander Ophir, chair of psychology at Cornell, called her a maverick whose work pushed you to rethink everything you were studying.

Finlay was born on 25 October 1950 in Pittsburgh, with fraternal twin siblings, Kathy and Bill, arriving less than two years later. As a child she leaned toward history and politics. In 1967 she took a place in a high school science program at Indiana University mainly to spend a summer away from her parents. Her six weeks in a lab, helping an optometry master's student test how well people tell triangles from circles, did not thrill her. But she read James J. Gibson's "The Perception of the Visual World" in a library copy, and as she said in a 2025 interview, it knocked her socks off. Back home, a TV program on David Hubel and Torsten Wiesel recording from neurons in cats settled it for her.

She earned a B.A. in psychobiology at Oberlin in 1972 and a Ph.D. in brain and cognitive sciences at MIT in 1976, then joined Cornell's psychology department as an assistant professor that same year. Her early work looked at the developing visual system, including cell death and how thalamic projections find their targets. The 1995 paper, her most cited with more than 1,100 citations, marked a turning point. Christine Charvet, now an assistant professor at Auburn University and a former postdoc of Finlay's, said tying developmental parameters to adult structure was truly innovative.

Finlay spent roughly the next 20 years refining the model. In 2001 she built a table to let researchers translate time, finding equivalent developmental ages across species. By 2013 the model held 271 events in 18 mammal species and covered the first three years of human development. Charvet took over the project when she opened her own lab in 2018; it now holds 1,000 events, and she is working to extend it across the entire human lifespan.

Those who knew her describe a voracious reader. Former graduate student Jeri Janowsky recalled stacks of books at Finlay's bedside that she would finish in an evening. Her son, Will Vineyard, said any topic was fair game, perhaps except military history. Malcolm MacIver, a Northwestern professor and close friend, said a conversation could move from brain evolution to metabolism to robotics to the evolution of eyes. She could also be hard to follow: she spoke elliptically, sometimes mumbled, and jumped between ideas. Maimon said he often understood something she said two or three years later.

She was funny, too. Her daughter Laura Vineyard recalls being told as a child that deer do not shut their bodies off when they dream, so they wander into trouble while asleep. Laura believed it until she was 25; Finlay had forgotten, but laughed and laughed. At Cornell she chaired the department for five years, a term Ophir says is still cited as the standard, and she threw rambunctious department parties. Maimon's thesis experiments in her lab never worked, he says, yet he lists her on NeuroTree as a mentor, a field that usually holds only graduate and postdoctoral advisers. For more than 20 years she co-edited Behavioral and Brain Sciences, and co-editor Paul Bloom said she wrote careful feedback even when rejecting young researchers.

Finlay retired in 2016 but stayed a fixture on campus and kept publishing, on the water-to-land transition, the case against human exceptionalism, and how grandmothers' societal role shaped brain evolution. She was diagnosed with endometrial cancer in 2021 and entered hospice in June this year; her children say her mind stayed sharp. When Maimon visited in August, she told him about an April Fools' prank from the 1990s: at some students' urging, she staged a seminar by a fake visiting professor, played by a hired local actor reciting an hour-long script of nonsense about throwing angry animals at study participants. At the end, the conspirators took a bow. Asked why she did it, she said, "Because it was fun."