Advances in microanalysis: Magnifying the social microscope on mother-infant interactions

Microanalysis is a method for recording and coding interactional behavior. It has been often compared to a social microscope, for its power in detailing the second-by-second dynamics of social interaction. Microanalysis has deep multidisciplinary foundations, that privilege the description of interactions as they naturally occur, with the purpose of understanding the relations between multiple and simultaneous streams of behaviors. In developmental science, microanalysis has uncovered structural and temporal elements in mother-infant interactions, improving our understanding of the effects of mother-infant interpersonal adaptation in the infant's cognitive and social-emotional development. Detailed manual coding is time intensive and resource demanding, imposing restrictions to sample size, and the ability to analyze multiple behavioral modalities. Moreover, recent increases in the density of multivariate data require different tools. We review present-day techniques that tackle those challenges: (1) sensing techniques for motion tracking and physiological recording; (2) exploratory techniques for detecting patterns from high-density data; and (3) inferential and modeling techniques for understanding contingencies between interactional time series. Two illustrations, from recent developmental research, reveal the power of bringing new lenses to our social microscope: (1) egocentric vision, the use of head mounted cameras and eye-trackers in capturing the infant's first-person perspective of a social exchange; and (2) daily activity sensing, wearable multimodal sensing that brought mother-infant interaction research to the environments where it naturally unfolds.