The Perceptual Crossing Experiment (PCE) captures the capacity for social contingency detection using real-time social interaction dynamics but has not been externally validated. We tested ecological and convergent validity of the PCE in a sample of 208 adolescents from the general population, aged 11 to 19 years. We expected associations between PCE performance and (a) quantity and quality of social interaction in daily life, using Experience Sampling Methodology (ESM; ecological validity) and (b) self-reported social skills using a questionnaire (convergent validity). We also expected PCE performance to better explain variance in ESM social measures than self-reported social skills. Multilevel analyses showed that only self-reported social skills were positively associated with social experience of company in daily life. These initial results do not support ecological and convergent validity of the PCE. However, fueled by novel insights regarding the complexity of capturing social dynamics, we identified promising methodological advances for future validation efforts.