This chapter addresses the question whether individual learning can be understood as a selection process that runs parallel to natural selection. The basis of the analysis is a selection-theoretical framework that considers selection as a result of the average joint occurrence (i.e., covariance) of behavior and signals for evolutionary fitness. We propose an extension of the principle of selection to individual learning that equally explains behavioral changes at the population level (phylogenesis) and behavioral changes at the individual level (ontogenesis): the Multilevel Model of Behavioral Selection (MLBS). The aim of this chapter is an informal introduction to the basic principles of the MLBS, which is conceived as a general theory of behavior. The chapter concludes with an overview of current work on theoretical and practical implications of the MLBS in behavior analysis and learning psychology.