The transmission of knowledge and skills to the next generation, the process of education in formal and informal settings, is inextricably bound with the emergence of Homo sapiens over the past several hundred thousand years (Bruner, 1960; Donald, 1991; Tomasello, 2000). Formal schools, however, are just a few thousand years old, and the notion of universal education, in which all young persons in a society receive several years of competent schooling, is still a distant dream in many corners of the globe (Bloom, 2003; Bloom and Cohen, 2001).