<p>It is highly variable. Generally science, math, and engineering classes any top tier university will not take attendance, for both lectures and section (section is usually just for review of lecture). Sometimes, though, discussion sections for humanities classes will take attendance, since participation is part of your grade.</p>
<p>Occasionally lectures will have mandatory attendance, but there is not difference in attendance policy between any of the top universities, so this is not going to be a factor that differentiates top universities like MIT, Harvard, etc.</p>