Behavioral psychology is a branch of science devoted to identifying principles of behavior through experimental study. Behavioral learning theory is the application of those principles to learning. To speak of behavioral learning theory as if it has emerged from a single line of research in which each subsequent researcher were influenced by and built upon the work of his predecessors within a very narrowly defined program of study is a misrepresentation of history. O’Donohue and Kitchener (1999) noted that there are “at least fifteen” varieties of philosophical and psychological behaviorism (p. 2). While some have built very directly and explicitly on the foundation of those that have gone before them, others have acted fairly independent of both their predecessors and their contemporaries. Only a few have directly influenced education, and those few—although distinct in their original form—have been merged, not by their creators or any select organizing committee, but by practitioners, into a general theory of learning based on the behaviorist tradition. This practitioners’ theory is founded primarily on the work of Burrhus Fredric Skinner (1904-1990), and it is Skinner’s principles of operant conditioning, contingencies of reinforcement, and reinforcement schedules, which receive the greatest attention in behavioral learning theory chapters of contemporary educational psychology textbooks (see, for example, Bohlin, Durwin, & Reese-Weber, 2009; Driscoll, 2000; Eggen & Kauchak, 1999; Mowrer-Popiel & Woolfolk, 1998; O’Donnell et al., 2007; Ormrod, 2003; Sternberg & Williams, 2010; Woolfolk, 1998; Woolfolk, 2010). Skinner, however, does not anchor the foundation of contemporary behavioral learning theory alone. The contributions of several individuals will be discussed in the following section (including Skinner), roughly in the order in which their most influential publications relevant to behavioral learning theory were made. This ordering is in no way absolute, has been selected simply as a matter of organization, and should not be taken to present a concrete chronological evolution of ideas. As behavioral learning theory is only one of five theories that will be reviewed, this discussion will be necessarily brief. Many excellent books are readily available for more detail (especially informative are, Bower & Hilgard, 1981; Hilgard, 1948; Hilgard & Bower, 1966; O’Donohue & Kitchener, 1999; Olson & Hergenhahn, 2009).