Yes. In science and history classes, I usually had somebody sneaking glances at my papers, and a couple people even asked me to change the angle at which I held the paper. Beyond that, I saw plenty of people writing little things onto papers, I was the king at notetaking in calculators, coming out of a class would prompt a rapid discussion with students going in wanting a heads up, et cetera.
Your college conclusion has some merit. It is less common, but it's still there. I believe the fundamental difference is that people don't know each other as well as they did in high school. I've still seen notes scribbled onto the the desks, smartphones glowing under a table, et cetera.