" Recently, two labor economists at the University of California, Philip Babcock and Mindy Marks, analyzed surveys of time use by college students from the 1920s through the present. They found that in 1961, the average full-time college student spent twenty-four hours a week studying outside of the classroom. By 1981, that had fallen to twenty hours a week, and in 2003, it was down to fourteen hours a week, not much more than half of what it had been forty years earlier. This phenomenon transcended boundaries: “Study time fell for students from all demographic subgroups,” Babcock and Marks wrote, “for students who worked and those who did not, within every major, and at four-year colleges of every type, degree structure, and level of selectivity.” And where did all those extra hours go? To socializing and recreation, mostly. "
― Paul Tough , How Children Succeed: Grit, Curiosity, and the Hidden Power of Character