Is publishing papers with many co-authors detrimental to one's academic career?

Question

I’m looking at some friends’ works, at good labs, in good schools, but some of their publications have 10 co-authors – I even found one with 15 co-authors.

I’m sure the lab and its PI(s) are doing well from such collaborative efforts, but at the individual level, are the PhD students being harmed, because the authorship is spread among so many people? I wonder if this kills their chances of securing post-docs later on, because they published with a big team of people, and I wonder if this signals that they have not done enough ‘independent’ work.

FWIW, those papers are in medical machine learning.

Answer 1

As mentioned in comments, the normal number of authors on a paper depends heavily on the field.

The issue with getting a postdoc is that you need to demonstrate your ability to do research. That doesn't necessarily mean you need to be the PI, as in some fields as a postdoc you would still be working on projects driven by someone else.

Having one or more individual papers would be one method of doing that. Being lead author on a paper in a field where order denotes role would be another. But for a PhD student applying for postdoc positions, their references will still play a big part in whether they are hired. Their supervisor should be able to include in the reference what part the student contributed to the paper.

Answer 2

Apart from the fields, in your CV you need evidence of being able to do your own research, and to collaborate successfully. Papers with a high number of authors, especially if interdisciplinary, are evidence of the latter.

Answer 3

As others have said, this is highly field dependent. In my subfield of computer science (called human computer interaction), having multiple authors could actually be helpful. It gives more exposure to your work; for example, the paper would appear on each of the authors' web pages resulting in more researchers seeing your work. The Co-authors are likely to advertise for the paper to give it even more exposure. More exposure means that more people will build over your work and hence this contributes positively to the field in general.

What you should care about is your position in the authors list. This is also field dependent, but in most areas the first author gets the highest credit, the last one or two are seen as the supervisors, and the ones in between are seen as contributors (with contributions of different sizes).