The appeal and popularity of "building blocks", i.e., simple and dissociable elements of behavior and experience, persists in psychological research. We begin our assessment of this research strategy with an historical review of structuralism (as espoused by E. B. Titchener) and behaviorism (espoused by J. B. Watson and B. F. Skinner), two movements that held the assumption in their attempts to provide a systematic and unified discipline. We point out the ways in which the elementism of the two schools selected, framed, and excluded topics of study. After the historical review, we turn to contemporary literature and highlight the persistence of research into building blocks and the associated framing and exclusions in psychological research. The assumption that complex categories of human psychology can be understood in terms of their elementary components and simplest forms seems indefensible. In specific cases, therefore, reliance on the assumption requires justification. Finally, we review alternative strategies that bypass the commitment to building blocks.