In Chapter 10, Lee Jussim gets to the question of why inaccuracies and bias in human perception get more attention than accuracy. On page 153 he addresses an aspect of the issue that I think is most salient to my concerns as an educator: If we believe that a person is unskilled, under-qualified, under-accomplished, or whatever because our perceptions are inaccurate, then "all" that we need to do is change our perceptions. That isn't always easy to accomplish as a seamless thing, it often requires conscious effort, but, in the end, bringing yourself to say "You know, he/she is actually pretty talented; I'll hire them/admit them to college/etc." is still easier than saying "Uh-oh, this person is way under-prepared, we have work to do to fix that." Any research that tells us that problems can be fixed by thinking differently is going to attract more support from the intellectual class than research that tells us that we'll have to do a lot more work on problems that stubbornly defy easy solutions.
On page 158, Jussim also notes that social psychology is more fun if you find bias and inaccuracy. If people generally perceive things pretty accurately then what is there to say? What need is there for a consultant? People will figure things out and, um, yeah. But if bias and misperception are everywhere then there's something to work on. This is akin to issues of publication bias in other areas of science. Perhaps bias research is biased in favor of bias research?
If the concerns in the first paragraph are largely social and political, and the concerns in the second paragraph are technical and pecuniary, then I think there's also a third contributor to the intellectual zeitgeist: Negative results from Western intellectuals in the 20th century. From them, we learned that measurements of distance and time are not absolute, but rather depend on how you are moving relative to someone else. (Einstein) We learned that mathematics is incomplete, and contains statements that cannot be proved by pure logic. (Godel) We learned that matter is not composed of solid particles with fixed positions and motions, but rather is "fuzzy" and smeared out, with uncertain positions and velocities. (Schrodinger, Heisenberg) Then Turing taught us that computers, the defining technology of the modern era, would have limits to what they could compute. Subsequently, Arrow taught us that it is impossible to even construct reasonable and egalitarian procedures for picking a winner in an election!* All of this set the stage for post-modernism and numerous other ideas from French intellectuals, and ultimately led to classmates in the 1990's telling me that scientific truth is just, like, a social construction, man.**
Mind you, I would happily argue that relativity, quantum mechanics, formal logic, computer science, and election theory should not be taken as death knells for ideas of objective knowledge and accurate perception. I would be happy to argue that all of these ideas are misinterpreted. However, if we are discussing how these topics are viewed by the educated classes rather than how they ought to be viewed then I think it's clear that the zeitgeist is favorable to the notion that humans can't really, like, know anything. And, having just graded a stack of final exams, I am also favorable to the notions that most humans are unable to, like, know anything! :)
*What Arrow's Theorem really says is a bit more subtle than that, but let's leave that aside for now. Some other time I'll argue that the Gibbard-Satterthwaite Theorem can be interpreted as a theorem about conflicts of interest.
**However, the "science wars" of the 1990's, in which some humanities scholars went way too far in their critiques of science, became irrelevant after the 2000 election. The academic community found a new common cultural enemy, and recently I read an article (can't find the link now) in which one combatant on the left wing of the "science wars" now finds himself on the side of objective scientific fact when facing right-wingers who argue that global warming is just, like, your opinion, man.