I bought "The Bell Curve" when it came out, and like I do with most "serious" books, I read it through, made notes and checked the sources (harder to do back then than it is now, usually involved a trip or six to an academic library). I usually find a <5% "bum steer" rate (i.e. references to vanity publications and non-peer reviewed work). Murray and Herrnstein's offering had >35%, more than a third of which were references to publications funded by the likes of the Liberty Lobby, pseudo-academic journals that publish articles about such things as the biological basis of racial inferiority, often using the same rhetorical style as Onar - the bulldozing conflation of disparate and mutually-unsupportable assumptions. The sort of intellectually-bereft dreck that could be used to fertilise deserts, it's so rich.
Even Murray himself eventually apologised for the poor quality of his research, claiming (possibly even honestly) that he hadn't realised that the journals wre kack.