<p>@PetyrBaelish - You should include all ECs you believe strengthen your application. Listing too many is unlikely to hurt you as long as you first list those for which you have had leadership roles or consider important. You should take great care with this section of the application - my advice is to describe each EC as it were a job description on a resume or CV. If you are just a casual member, describe your involvement as best you can, or omit it if you don’t think it is relevant.</p>
<p>All of these schools (including MIT) practice holistic admissions and require you to take courses in a wide variety of subjects, thus they favor people with diverse interests and capabilities over those who are strong at a single subject - the exception being academic superstars.</p>
<p>Few selective colleges in the US require you to apply for a specific course of study, and for most (some exceptions being Columbia, Duke, and CMU), you apply to the college as a whole, not to a school within the college, then chose your major later - be it biology, chemical engineering, economics, or philosophy. Many will ask you to list a prospective major, but it’s unclear whether this affects admissions decisions or not.</p>
<p>In my opinion, your will enhance your odds by emphasizing how you differ from other applicants, rather than trying to craft a perfect application that could as easily have come from Des Moines as Brunei.</p>