Recent decades have opened up history faculties so that they include more female and minority scholars. But a new report released by the American Historical Association says that in key respects history departments are becoming “less diverse.” Top doctoral programs are admitting Ph.D. students from a narrow group of mostly private institutions and top departments are in turn hiring from a narrow range of institutions, the report says.

The preference of elite institutions to admit graduate students from other elite institutions is, of course, nothing new. But the history report says the discipline — having become more egalitarian — is now shifting back with regard to its mix of public and private graduates.

In 1966, 57 percent of history Ph.D.’s had received their undergraduate degrees from private institutions, 37 from public institutions, and the remainder from international institutions. In the 1980s, public and private graduates had achieved parity. But in the 90s, the gap returned, growing to a 47-42 percent edge for private institutions, even though far more undergraduates attend public institutions.