Science is a team sport, and those teams are getting bigger. This expansion may enable researchers to work together to answer complex biomedical questions, but recent research suggests that this trend is hindering the career prospects of PhD graduates.
The authors analyzed 40 years of data from a National Science Foundation survey tracking PhD recipients. They then combined this data with the average team size in a researcher’s field at the time of their PhD (based on the number of authors on published studies). They found that as team size increases, junior researchers become less likely to achieve tenure and secure research funding, and more likely to leave science altogether.
The findings, published last week in the journal Nature Biotechnology, come at a time when academia is grappling with an unprecedented exodus of life science researchers, a trend that is already affecting basic research in university labs.
To better understand the results and what they mean, STAT spoke with co-author Donna Ginther, a labor economist at the University of Kansas who has studied the scientific workforce for years. “As team size gets larger, it becomes harder to know who’s responsible for what,” Ginther said, making it harder to know whether someone has the capacity to work as an independent scientist.
She has previously researched the challenges facing postdoctoral researchers and was recently part of an advisory committee to the National Institutes of Health that recommended giving postdoctoral researchers substantial pay increases.
This conversation has been edited for length and clarity.
What did we already know about the role of teamwork in science prior to this study, and what did we not know that you were hoping to answer?
A lot of people have looked at what teams produce. There’s a great literature that says that larger teams tend to produce incremental science and smaller teams tend to produce revolutionary science. But very few have looked at the impact of teams on career outcomes. This project started in 2018 when I was on holiday in Australia. My other three collaborators are in Australia, and[co-authors]Catherine de Fontenay and Kwanghui Lim developed a theoretical model that shows that as team size increases, it becomes less clear who is doing what in the team, and the signal of contributions becomes noise.
They were interested in exploring the impact that it has on career outcomes, and what we show is that the average team size in your field at graduation impacts your career outcomes 10 years later: on average, larger teams reduce your chances of getting an academic job, your chances of getting tenure, your chances of getting research funding.
We collected data on PhD recipients across the sciences, from mathematics to physics, astronomy to biology. Was there anything special or different about the impact of team size in the biomedical sciences?
For life sciences, there is a natural experiment in that the NIH budget doubled (from 1998 to 2003), and we show that when the NIH budget doubled, team sizes in biomedical fields increased by one person compared to other life science fields and other fields overall, meaning that funding contributes to team size growth. However, we did not do separate analyses (of the effects of team size) by field because we were looking at what happens across fields and across time.
Were certain groups of researchers affected more than others?
For team size and women, the impact on tenure and research funding is exacerbated. Looking at the impact on foreign-born researchers, there is evidence of a further decrease in the likelihood of tenure, tenure and research funding, and an increase in the likelihood of becoming a postdoc.
The number of people entering science fields has outpaced the growth in faculty positions in recent years. Is the “team size” effect you report simply due to that trend?
I think that works, right? The number of tenured faculty members remains constant, and the number of graduate students increases, so naturally the size of the team and the lab also increases.
What do you think is the main reason why increasing team size negatively impacts the career prospects of early career researchers?
I think the problem is not knowing who is doing what. In a small team, the division of labor is pretty well defined. But as the team gets bigger, it becomes harder to know who is doing what without carefully reviewing contributions and not knowing if you can trust them. So you need more information to determine whether these people have the skills to be independent researchers.
At least in the life sciences, it is common for the order of authorship to be taken into account, with the first author being considered to have driven the project and middle authors assumed to have played a smaller role. Is it your contention that this practice does not make it entirely clear who did what?
I don’t think this question will ever be fully resolved, and we are conducting new research to look at author contribution statements to see who did what in a paper and see what information we can glean from that.
Based on these findings, are there any changes that could benefit early career researchers?
I think helping to identify individual scientists’ contributions to teams helps solve the information problem: author contribution statements, letters of recommendation that say this scientist did this research in these projects. Solving the information problem is one problem; how to reward teamwork is another. Is it good for teams to write more papers? Should we moderate the quality of those papers? I think this is a broad, open question that needs better answers.
What should doctoral students and postdocs take away from this research?
Individual researchers can use this information to choose which lab they want to join in the future. If you work with a big, well-known scientist with a lot of people in the lab, you won’t get their attention. You might not get the career development you need. If you work with a young, promising newcomer to the lab (a PI), you might get more attention. If you work with a smaller lab, you might get more opportunities. So you need to weigh these factors.
