One reason people attend, and stay in, school through high school, college, and beyond, is to become more intelligent. And while additional years of schooling should increase one’s store of general knowledge and career prospects, until recently research had not concluded that formal education also increased one’s IQ. But then a meta-analysis determined that each additional year of schooling appeared to raise IQ by one to five points. Exactly how schooling boosts IQ is not clear, though, nor is whether or how the effect accumulates over many years of education. But experts point to the study as a sign of a more crucial truth: that an individual’s intelligence can change over time.