Sir Isaac Newton was in his 20s when he developed his theories on calculus, gravity and optics.
English physicist Paul Dirac was 31 when he won a Nobel Prize for predicting antimatter.
Albert Einstein introduced the world’s most famous equation, E=mc2, at 26. He later said that “a person who has not made his great contribution to science before the age of 30 will never do so.”
“Especially in more abstract fields, people think the best work is done at earlier ages,” said Bruce Weinberg, an Ohio State University economist. “That’s not quite as clear a pattern as people think.”
In fact, the average age of scientists in the United States is increasing, Weinberg and fellow OSU economist David Blau found in research published Monday. The average age of employed scientists rose from 45.1 to 48.6 between 1993 and 2010.
“The workforce as a whole is aging,” Blau said. “But (this rate) is pretty specific to academia.”
At Ohio State, 37 percent of tenured or tenure-track STEM faculty members are 55 or older.
“This is happening across the country,” said Jan Weisenberger, senior associate vice president for research and a speech and hearing science professor at Ohio State.
The finding makes sense to Ohio State astronomy professor emeritus Brad Peterson, who said there are incentives to delaying academic retirement. Through long careers, scientists maximize their expertise and professional connections.
“You become a known quantity,” said Peterson, who officially is retired but still teaches and works as a distinguished visiting astronomer for NASA’s Space Telescope Science Institute. “Scientists are curious, driven people. Any good research turns up two or three more research questions. There’s no end in sight.”
The OSU economists don’t yet know whether the graying research community means that budding scientists are missing out on opportunities — or what the trend means for scientific creativity and productivity.
“If there are more older researchers, and they were to retire, it’s hard to know how many slots that would open for younger scientists,” Weinberg said.
The study, published this week in the journal "Proceedings of the National Academy of Sciences," analyzed data on the age, field of degree, job tenure, occupation and sector of employment of about 73,000 scientists. The pool spanned STEM fields from mathematicians to social scientists and included researchers at university labs and those working in the private sector for biomedical, pharmaceutical or tech companies.
The general aging of scientists and engineers can largely be attributed to Baby Boomers nearing retirement age, Blau said. That effect gradually will fade away.
“Eventually the huge Baby Boom bulge will pass,” he said.
But changes in retirement laws have contributed. Many professors have extended their careers since the 1994 abolition of mandated retirement.
According to the new study, the share of scientific workers 55 or older almost doubled between 1994 and 2010, from 17 percent to 33 percent. Over the same period, the share of all workers in that age bracket increased less, from 15 percent to 23 percent.
“By age 70, most people have retired. That’s not necessarily true of science,” Weinberg said. “We’ve observed a big pileup of people who didn’t have to retire anymore.”
Mary Ellen Wewers, a public-health professor emeritus at Ohio State, might be counted among them. She retired from her position as an associate dean for research but still teaches and is the co-principal investigator on a five-year, $18 million project on tobacco control.
“That had always been my plan; I definitely didn’t want to give up my research career,” she said. “I still have a lot of work that’s important to get out there. I don’t intend to retire from research any time soon.”
The economists plan to continue studying what the advanced age of the scientific community means for its productivity. “We don’t know if they still are riding the arc of creativity or like hanging out in academia,” Blau said.
Hazel Morrow-Jones, professor emeritus of city and regional planning, still works part time at Ohio State, but as a retiree, she now spends more time on her garden.
“I was no longer concerned about establishing a reputation, or getting tenure, or the next promotion or getting a raise,” she said. “I could bring the most to the job.”