Several posters have opined that LSAT and MCAT reading comprehension sections are similar/different/whatever. Let's get specific, for purposes of studying for MCAT:
- LSAT passages are more predictable in structure than MCAT -- their length does not vary much, the number of questions varies less. They are rarely other than three, four, or five paragraphs. Relevance to MCAT study: essentially none.
- LSAT questions are roughly the same, though sometimes the differences between answer choices are more subtle and finding the correct answer more a matter at looking at tiny details in wording than at understanding larger issues (but even on MCAT Qs, the way to find the answer is almost always in the details anyway). Relevance: low, though you?re using slightly different skills.
- In LSAT the number of ambiguous and awkward questions is essentially zero, not true in MCATland. Relevance: none.
- LSAT passages have more predictable subject matter: each LSAT section has one each of hard science; social science or history; art or literature; and law. The law passage doesn?t really happen on MCAT, but the others do. The science tends to be a little easier, unsurprisingly; the literature averages more difficult to read. Fiction is nearly unknown on the LSAT. Still, any LSAT passage could appear, or resembles something that could appear, on the MCAT, though the converse is false. So the relevance of this fact is low.
LSAT timing is different: because of the smaller amount of time and of passages, huge decisions need to be made (the difference between completing, say, two and completing three passages is huge; on MCAT, the difference between seven and eight is small). This is relevant if you are doing LSAT sections, but not if you are just doing a passage at a time.
LSAT sections, and to a lesser extent passages, are more difficult to do in the allotted time. Relevance: essentially none, except to the extent you are playing with your timing.
Bottom line: of course they?re different, but LSAT passages are still very good material on which to practice for MCAT verbal.
(background: I teach, and have taken, LSAT and MCAT. GMAT, too: it's far easier than, and not as helpful as, LSAT.)