From Daniel Willingham at the New York Times:
Regarding a collection of Americans in 2003:
Of those who finished high school but did not continue their education, 13 percent could not perform simple tasks like these. When things got more complex — in comparing two newspaper editorials with different interpretations of scientific evidence or examining a table to evaluate credit card offers — 95 percent failed.
Your ability to understand a news article or passage is very dependent on having an appropriate level of background information at your grasp. You can make the correct inferences of the writer’s intent.
Key lesson: do not let lack of subject matter knowledge impede comprehension.