Here's some of
LizzyM's posts. She actually sits on an adcom as opposed to the rampant idle speculation by all the rest of us pre-meds.
Some of her posts on the topic:
"Hmmmm... you can get away with a gpa that is -0.2 to -0.4 below the med school mean provided that 1) the school is highly regarded academically, 2) your major was considered a difficult one (engineering almost anywhere) and 3) your MCAT scores are at least a point above the med school's mean in each of the three sections."
"If your undergrad college was easy to get into and admitted most applicants with SAT scores of 1000 and above, then you are going to be considered a big fish in a small pond (it might be easier to be an academic stand-out in that school than at a school where most of the students had SATs of 1400 or better). So, you not only have to have an exceptionally high gpa but you need to do at least as well on the MCAT as the students from the "well-known" schools (level playing field & all that). A MCAT below a med school's average is not going to go over big if you are from a school that is not an academic power-house."
"You know that it is easier to get into some undergrad institutions than others. You know that the average SAT score at some schools is 1400 and at others it is 1000.
Now imagine that both schools teach Chem 101 and grade on a curve. If you are talented enough to get into either one, you are going to earn a higher gpa at the school with the "on average" less talented students (given the same amount of effort). Even if there is no curve, an exceptionally talented student is going to be "average" at a top 10 research university and "well above average" compared with fellow students at Smallville State College or Faithfilled Bible College.
So, the medical schools see a 4.0 or 3.7 frmo Smallville or Faithfilled and they don't consider it comparable to a similar gpa at a "name brand" school because the caliber of students is "on average" not as high. A very high MCAT can provide evidence to disprove the "big fish in a small pond" phenomenon that we sometimes see at no-name schools."