A quarter century of research on infant contingency learning: Current and future directions.

Although traditional learning paradigms provided a substantial base for the emergence of the field of infant studies from the 1960s through the 1990s, research on contingency (operant) learning in infancy has not attracted much attention over the last 25 years. While the reasons for such neglect are unclear, learning protocols offer valuable contributions to the field of infant studies, spanning basic research, translational work, and application. An examination of the literature over the last quarter century shows operant learning concepts in use with respect to the development of agency, goal blockage reactivity, clinical cross-group comparisons, and developmental interventions. Building upon the foundation that infants are capable of contingency learning, research has explored underlying mechanisms, including coordinated movement dynamics and psychobiological correlates. Methodological innovations-such as novel paradigms and cutting-edge techniques like motion capture, eye-tracking, and computational modeling-have further refined our understanding of these processes. Efforts have also focused on identifying conditions that promote learning and factors contributing to data loss. An overarching question remains whether infants demonstrate agency during contingency learning. Additionally, recent research has shifted from a primarily experimental group approach to considering individual differences in early learning. However, it is unclear whether traditional learning metrics effectively capture nonmonotonic behavioral change and variability in learning patterns. The review offers cogent rationales for reintegrating these paradigms into the field of infant studies, discusses gaps in the literature that should be addressed for this goal to be realized, and proposes future directions for advancing the field.