According to research from Harvard, as many as 40% of kids who intend to go to college at the time of high school graduation don’t actually show up in the fall. Education researchers call this phenomenon “summer melt,” and it has long been a puzzling problem. These kids have taken the SATs, written college essays, applied to and been accepted by a school of their choice. Often they’ve even applied for and received financial aid. Why would they not show up at college? This week on Hidden Brain, we look more closely at the problem — and talk about ways that some universities are trying to fix it.