Brooks, David (2011-03-08). The Social Animal: The Hidden Sources of Love, Character, and Achievement (p. 107). Random House, Inc.. Kindle Edition.
Students from the poorest quarter of the population have an 8.6 percent chance of getting a college degree. Students in the top quarter have a 75 percent chance of earning a college degree. As Nobel Prize–winning economist James J. Heckman had found, 50 percent of lifetime-earnings inequality is determined by factors present in the life of a person by age eighteen. Most of these differences have to do with unconscious skills—that is, attitudes, perceptions, and norms. The gaps in them open up fast.”