Scientists produce less disruptive research as they age, but their breakthroughs are more likely to last

This article has been reviewed according to Science X's editorial process and policies. Editors have highlighted the following attributes while ensuring the content's credibility: Science often advances in small steps, with researchers gradually building on previous discoveries. But every now and then, a breakthrough comes along that challenges conventional thinking and changes the direction of a field.

It is generally thought that scientists do their most disruptive work when they are younger, and as they get older, these kinds of breakthroughs become less common. But new research suggests that is only part of the picture. Researchers led by Nan Deng at the National Science Library, Chinese Academy of Sciences, wanted to know whether a scientist's ability to produce lasting breakthroughs changes over their career.

Standard measures of disruption tend to focus only on whether a paper overturns prior work, ignoring whether that disruption itself endures over time. In this latest study, the team analyzed 11.2 million papers published by more than 200,000 scientists, all of whom had research careers spanning more than 40 years. The team focused on citation patterns and looked for two things: whether a paper overturned prior work and whether that disruption itself endured.

To track these patterns, they relied on a standard metric known as the Consolidation-Disruption (CD) index, which tracks whether a paper introduces a new direction or builds on existing work. But because the standard index only shows if a paper displaces old ideas, the researchers used an additional metric called persistent disruption (PD). This shows whether a discovery continues to guide a field or is quickly replaced itself.

The findings, published in the journal Proceedings of the National Academy of Sciences, show that career age is associated with disruptive ideas in two very different ways. Early in their careers, scientists are more likely to produce highly disruptive papers. But as they gain experience, the nature of their work shifts, as the study authors note in their paper: "Scientists may become less likely to produce disruptive work as they age, yet the disruptive work they produce is more likely to persist." The researchers put some figures on it.

They found that the probability of producing a persistently disruptive paper rises steadily throughout scientists' careers. It more than doubles from about 1% in their early years to 2.2% by year 40. However, this shift is not simply due to biological age but is primarily associated with cumulative research experience, according to the authors.