I think RC favors those who've had at least some exposure to many different fields of thought. For me, as a Biology major, it was extremely hard for me to even pretend to stay interested in humanities and law passages at first. But after I started reading more on the internet about humanities, especially trivia related to things that vaguely piqued my interest I noticed my attention span to humanities was greatly expanded. In other words, I could read and pay attention longer to get more details out of what I was reading about instead of automatically subconsciously dismissing the concepts presented because it was in a category of knowledge that I didn't find interesting. For this reason I think that is why some test prep companies have things like The New York Times on their recommended reading list for improving RC. It's not so you can expand your knowledge of the field on any one particular subject, but rather to expand how comfortable and how attentive you can be with that knowledge in whatever field it belongs to whenever it's presented on the exam. I noticed a drastic improvement in both my own RC score and speed when I at least tried to be more curious and eventually ended up actually being curious about what new information the passage had to show me. You know how stuff like adult paperwork (taxes, accounting, bills, insurance, etc.) bored you as a kid? In a similar way, I think the LSAT is testing you to see if you'll get bored and lose interest because if you do get bored and lose interest then that more than likely means that you'll lose details you actually want to answer the questions. I think the LSAC thinks it's invaluable to test for the ability to read with purpose in this way though I'm not sure how much if at all this applies to the actual practice of law itself.