The problem, Brian, is that there so much spin around, so many "histories" fabricated for propaganda purposes with varying degrees of accuracy. Social sciences, especially anthropology and history, are particularly notorious for selective treatment of factual information to "make a point" about Western society (i.e. that is either good or bad), but then there is political science, economics, sociology, "regional studies," "ethnic studies" and so on. As a result you face a deluge of information that it resemble Jorge Louis Borges' "Library of Babel" http://jubal.westnet.com/hyperdiscordia/library_of_babel.html and that you really need to engage in serious research effort to sort myth from fact.
The fact of the matter is that few people, especially those with broad interests, have enough time and energy to investigate every claim made in every book of interest to them. Out of necessity, you need to take what is printed for its face value. In the past, high transaction cost of the print media effectively reduced the amount of bullshit to government propaganda (which is relatively easy to deconstruct) - but with the ascent of internet publishing those transaction costs went almost to zero, so anyone can publish whatever one wants with very little cost. Of course, not everything that is published today is bullshit, but by the sheer law of probability, an increase in the overall volume resulted in an increase of the volume of bullshit.
I do not know what the solution to this problem is (a reputable internet site debunking published myths?), but it certainly is not "better check what you read."
Wojtek