In a recent post on 49 percent, Samia asks a tricky question:
Wouldn't it be easier to land a faculty position/eventual tenure if I operated like a state scientist and established myself as an expert in one teeny, tiny area? How do minority (racial, gender, any kind) PI's fare under the "nomad" path? Why do I cringe inwardly when my advisors tell me I need to specify my interests? I feel like if I do that, I'll be limiting my opportunities in the future. Am I crazy? Tell me I'm not crazy.
You are not crazy. Unfortunately some aspects of the system are crazy and it would be best to recognize this.
There are at least two different issues at hand here so let me deal with the easier one first. From what she writes on the blog, Samia is an undergraduate considering graduate studies. Consequently the advisors who are telling her to specify a relatively narrow interest within some -ology or other may be thinking about the graduate school application process. The statement of research interest is in many departments almost comically specific. Generic grad school application advice says to tailor the statement to each department you apply to, with a heavy nod to the research of the current faculty. In some cases one might even pick out two or three labs and wax extremely specific about their work. This is one of those convenient fictions. The positive reasons for this, in my view, are to determine if the applicant has a clue about the department and a clue in general; everybody knows the first semester or year of graduate school is to decide what you really want to work on.
The eventual career trajectory question is much trickier.
The straightforward part is that many promotions committees express a view that they are looking for evidence of an essential seminal contribution made by the junior faculty member when considered for tenure or Full Professor. Practices can vary with respect to when the "seminal contribution" is expected, and lower down the ladder the theme is "potential for a seminal contribution". Part of the analysis also tends to rest on the candidate for promotion being recognized internationally as a "top expert in their field"; in practice this means sub-sub-sub-field. This latter being the obvious way to define the scores of junior faculty in your -ology as top 5 or so experts.
This is why much advising of junior faculty urges them to focus very narrowly on a specific area of science. So that their CVs will testify to a unified program of research that is highly unique and quite clearly the assistant professor's own domain of (unique?) expertise. I have heard some rather comical extremes of this presented to colleagues under guise of career advice.
The trouble, of course, is that this can be a really constraining way to do science. Some people's interest are going to be broader than others. Some people have experimental ADD. Sometimes the most effective science follows threads that jump across techniques, models and experimental approaches over time. Unfortunately, promotions committees may not deal very well with complexity. Nor deal well with reference letters that speak to one half or one third of the research program and remain silent on the part that is out of the referee's sphere of expertise.
It is a tough balance if you are one of those folks with normal to broader interests. Because I'm here to tell you that if you can't do what you want as a junior PI, well, it may not be worth it. Yes you need to be strategic and tactical and play the games...but at some basal level you have to be able to do your stuff your way...or you are going to burn out in short order.
It is also a tough balance because some minority of the people reviewing you for a job or promotion may actually get it and appreciate breadth. Not to mention a diversity of projects makes keeping your lab funded that much easier because you can seek funding from different agencies- or at the very least different NIH ICs.
One compromise that I see working is that the PI ensures that she has a story to tell that provides that narrow-focus narrative within a greater actual scientific diversity of her program. Maintaining a core theme running through the lab that can be easily described and may even be readily apparent from a casual review of the CV. With respect to this latter, I once had a colleague relate how she was told by a mentor to include certain terms in the titles of her next few papers. The goal was to enhance the natural pop-out of the theme she decided was going form her narrow-focus narrative.
A final thought stems from my life-is-too-short perspective. Ultimately a scientist has to do the stuff that interests her and that makes the most logical sense. If that is skipping from topic to topic, well, so be it. Just keep yourself aware of the risks you run by doing so.