Two theoretical perspectives—functionalism and constructionism—predominate modern research on emotion. This introductory chapter describes these perspectives and offers points of convergence and divergence. It pays special attention to common misconcep tions about functionalism and to the strengths and limitations of each perspective. Func tionalism, which draws in part from phylogenetic accounts of emotion and motivation, is limited by difficulties drawing inferences about human emotion from animal research, even though animal research is conducted using very precise methods of high spatial and temporal resolution. In contrast, constructionism is limited by difficulties falsifying its core propositions given reliance on research using functional magnetic resonance imag ing, which has poor temporal resolution. These limitations notwithstanding, both func tionalism and constructionism have much to offer current interpretations of and future research on emotion dysregulation. Thus, pitting the perspectives against one other is counterproductive.