Research Institutions Worldwide Are Growing More Alike in What They Study

When a university hires a scientist, it is not just filling a vacant office. According to a new study from the Complexity Science Hub in Vienna, conducted together with Leiden University, that decision is quietly reshaping the intellectual landscape of global science. Analyzing the careers of 9.3 million researchers at 3,965 institutions worldwide between 2000 and 2020, the team found that research organizations have steadily converged on increasingly similar sets of topics, while new hires tend to slot into the existing thematic profile of their new employer with remarkable precision.

The study, published in the journal Scientometrics, drew on 25 million scientific publications and traced the publication histories of their authors across two decades. Rather than looking at broad disciplines, the researchers used an established classification system that distinguishes 4,163 narrow, specific research topics. On a scale from 0, meaning no overlap, to 1, meaning identical topics, the median alignment between a new hire’s research and that of their new institution came out at 0.84. At half of the institutions studied, the match was even tighter than that figure suggests.

We are not talking about broad fields like molecular biology or quantum physics, study co-author and Complexity Science Hub president Stefan Thurner notes. We are talking about very narrow, specific research topics. The finding means that when a laboratory or department recruits, it overwhelmingly tends to select someone already working on the same specialized questions, down to the level of fine-grained subfields that most outsiders would struggle to tell apart.

The convergence between institutions surprised senior scientist Vito D. P. Servedio of the Complexity Science Hub. I expected institutions to develop more distinct profiles, he says. Diversity in research can be valuable, because we often don’t know what knowledge we’ll need next. His concern touches on a tension at the heart of modern science policy: if universities worldwide drift toward the same thematic portfolios, the global research system may lose some of the redundancy that historically has protected it against dead ends and unexpected breakthroughs.

Prestige appears to amplify the effect. The team measured institutional standing by the share of an organization’s publications that land among the 1 percent most cited papers in their respective topics. By this definition, particularly prestigious institutions are more likely to hire researchers whose focus closely matches their own, Thurner says. The pattern held regardless of whether the new hire had previously collaborated with colleagues at the institution, suggesting that elite organizations actively select for thematic fit rather than simply absorbing collaborators they already know.

Collaboration itself, however, seems to be deeply entangled with alignment. For researchers leaving an institution, the median topic alignment was slightly higher than for new hires, at 0.86, which the authors interpret as evidence that scientists drift closer to their colleagues’ topics during their time at an organization. Among researchers who never published with colleagues at the institution, alignment dropped sharply, to 0.54 for new hires and 0.61 for those departing. We can’t say whether collaboration leads to greater topic alignment or the other way around, says first author Márcia R. Ferreira. But there is a connection. Since collaboration is something institutions can encourage, it may be a lever they can actively use.

The distribution of alignment patterns across institutions reveals distinct strategic archetypes. At 41 percent of the organizations studied, both incoming and outgoing researchers fit the institutional profile particularly well, with alignment above the median for both groups. This cluster includes Ivy League universities and leading European institutions, and it correlates strongly with citation impact: highly cited institutions cluster in the upper right of the team’s scatter plots, where both hires and leavers match the house profile. At 45 percent of institutions, alignment fell below the median for both groups, and most of these organizations showed citation performance at or below the global average.

One striking exception stands out. The Institute for Advanced Study in Princeton combines very low topic alignment with very high citation impact. It is built around visiting scholars rather than permanent hires, Ferreira explains. That shows more than one model can work, and high alignment is not a prerequisite for excellent research. The finding complicates any simple prescription that institutions should maximize thematic coherence. Around 8 percent of institutions tend to recruit researchers with complementary topics while seeing well-aligned researchers leave, and at 6 percent the pattern is reversed, bringing in close fits while losing scientists who diverge from the house agenda.

The strength of alignment also varies across disciplines. It is somewhat higher in the biomedical and health sciences, the life and earth sciences, and the physical sciences and engineering, and lower in mathematics and computer science as well as the social sciences and humanities, particularly at institutions with lower citation impact. In these fields, people more often work alone or in small teams, without shared labs or equipment, Ferreira says. One explanation could be that with less day-to-day collaboration, there are fewer opportunities for topics to converge. The infrastructure of a field, in other words, may shape its intellectual homogeneity as much as any hiring committee does.

Whether tight topical alignment is good or bad for science remains an open question, and the authors are careful not to oversell either direction. Earlier studies indicate that researchers who share a knowledge base can learn from one another more effectively and be more productive, an advantage that close-knit, thematically coherent departments clearly enjoy. But too much similarity may also slow innovation, the team notes, because every new hire is simultaneously a decision to build on existing strengths or to import new topics. Our method lets us measure, at scale, which path an institution actually takes, Thurner says. University leaders, funders, and policymakers could use it to check whether their hiring strategies match their goals, and to change course if needed. Where researchers go, their knowledge goes, and as the two-decade record shows, the destinations are looking more and more alike.

Subject of Research: Topic alignment and convergence in research institutions worldwide

Article Title: Research institutions are converging on what they study

Article References: Research institutions are converging on what they study. (n.d.). Original publication

Image Credits: AI Generated

DOI: Not provided

Keywords: scientometrics, research institutions, topic alignment, researcher mobility, prestige, collaboration, citation impact, hiring, Complexity Science Hub, innovation, interdisciplinarity, science policy