The age of invention: patents show differences between younger and older inventors

Illustration/Jessica Tanny

Patent filers are most productive around midlife, but some inventors continue to be productive well into their 60s or beyond, according to new research.

Some inventors continue to be productive well into their later years, although the characteristics of inventions differ by the age of the inventor, according to new research on patent filings.
 
The study, led by a group of Brandeis researchers, examined more than 3 million U.S. patents filed from 1976 to 2017 to identify certain attributes, and then analyzed them based on the age of the filers.
 
The research found older inventors are more likely to rely on their knowledge and experience, and build on novel applications of past inventions – what psychologists call crystallized intelligence – to develop a patent. Younger inventors are more likely to submit patents that are forward-looking and rely on abstract reasoning and novel problem-solving – all traits of fluid intelligence.
 
The findings, now available online, will be published in the journal “Research Policy” in January. The research was led by Adam Jaffe, professor emeritus of economics; and Margie E. Lachman, the Minnie and Harold L. Fierman Professor of Psychology and director of the Lifespan Development Lab at Brandeis, along with Mary Kaltenberg, formerly a post-doctoral fellow at Brandeis and now a professor at Pace University.

Patent filers were most productive around midlife, but some inventors continue to be productive well into their 60s or beyond. It is not unusual for inventors to file patents for the first time later in life – 22 percent of first-time filers were over 50 years old.
 
“The findings suggest that we shouldn't assume that creativity and inventiveness are only possible in early adulthood or early middle age,” Lachman said. “Although the peak of patents awarded are for those in midlife, there are inventors who are patenting well into later life.”
 
The study found that “backward citations” – drawing on previously-filed patents to develop a new invention – and “originality” – referencing a broad range of fields within a given patent – both increased with age. Younger patent filers, on the other hand, are more likely to file patents that receive more "forward citations," meaning the work is more likely to be referenced in future inventions. They are also more likely to file patents viewed as "disruptive," meaning they belong to an emerging field or a field likely to emerge in the future.
 
“By examining the lifetime patenting of over a million inventors, we are able to examine how this creative activity changes with age in an important real-world setting,” Jaffe said.
 
The analysis brought together Lachman and Jaffe, two accomplished researchers, in an unusual way. Lachman studies cognitive changes with aging, examining both aspects of abilities that improve with age and aspects that decline with age. Most of that research is done by examining age patterns using lab-based cognitive tests.
 
"We consistently find these patterns in the lab, but we don't know a lot about how performance on these tests applies in everyday life, in terms of how changes in these abilities affect their work, for example," Lachman said.
 
She thought perhaps patents could provide some real-world insight, and approached Jaffe, an economist who has studied patents and innovation for decades, who told her that not much is known about patents in relation to aging.
 
"It was surprising to me that when you apply for a patent, they do not ask for a birth date or age," Lachman said. "My wheels started turning."
 
Along with the analysis, the research resulted in a new database that could be fertile ground for future studies. Inventors do not disclose their age on patent filings, so the research team included a programmer who used a code to scrape the web to match patent filers with other publicly available information that identified their age. A group of undergraduate researchers in Lachman's Lifespan Lab checked the results and sorted through and worked to resolve conflicting information.
 
The study examined patents filed by individuals as well as by teams. The analysis of teams found that teams with a wider diversity of ages had slightly higher rates of forward citations, but that further analysis is needed to shed more light on how teams comprised of varying ages work together.
 
“We think this is an area that is worth exploring in the future and the new database can facilitate that work,” Lachman said.

The research was supported by a 2017-19 grant from the Alfred P. Sloan Foundation’s erstwhile Working Longer Program, which sought to “deepen scholarly, policy, and public understanding of older Americans' labor market activities and find ways to facilitate employment of those who need or want to work beyond conventional retirement ages.”