Eric Rasmusen of the Law Professor Blog Network points out that professors offer each other support but much depends on the situation and department.

At Missouri, Humanities Professors Support a Communications Professor; at Yale, Science Professors Support a Sociology and Psychology Professor

What induces professors to sign letters of support for their colleagues who are under attack? I was under public attack a few years back, and although few actual faculty members attacked me (the Chancellor being an exception, while chairing a faculty senate meeting and sitting fifteen feet away from me), none publicly supported me either, and I sensed an atmosphere of fear of public opinion. A couple of recent cases provide interesting data.

Roughly speaking, at Missouri faculty from the humanities supported a colleague under attack, and at Yale faculty from the sciences did, both with a few exceptions from other fields. What is interesting is that of the 116 Missouri signers, 84 were from humanities departments and just 4 were from science departments, while of the 90 Yale signers, 41 were from science departments and 6 from the humanities (all from language or music departments). I excluded psychology from science, but added math and computer science, and did the best I could for Yale to decide which professors in the medical school were scientists.

Missouri had 0 signers from economics, 0 from the business school and 1 from law. Yale had 3 from economics, 11 from the business school, and 1 from law. The Missouri professor was in communications and journalism (5 signers) and the Yale professors were in psychology and sociology (18 signers).

I need to add a caveat for Yale. I am Yale Class of 1980 and was disappointed that only 49 faculty had signed. I emailed the organizer, and he said the letter was not widely circulated— that, for example, Anthony Kronman was the only person he knew in the law school— although about half the signers signed after the news media report. I emailed 4 professors in economics and 12 in the law school whom I thought might sign. 1 from economics and 2 from law did. I didn’t include those people in my numbers above.