Psychological science has much to contribute to preK-12 education because substantial psychological research exists on the processes of learning, teaching, motivation, classroom management, social interaction, communication, and assessment. This article details the psychological science that led to the identification, by the American Psychological Association's Coalition for Psychology in Schools and Education, of the "Top 20 Principles from Psychology for PreK-12 Teaching and Learning." Also noted are the major implications for educational practice that follow from the principles.