In this study, the authors investigated the relation between early social contingency experiences and infants' competencies to detect nonsocial contingencies. In this study of 87 three-month-old infants, the authors operationalized early social contingencies as prompt, contingent maternal responses and coded microanalytically on the basis of video-recorded mother-infant interactions. The authors assessed competence to detect nonsocial contingencies by 2 methods: (a) the mobile conjugate reinforcement paradigm, which focuses on detecting contingencies between the infants' actions (kicking) and nonsocial consequences (mobile moving) and (b) the visual expectation paradigm, which focuses on detecting contingencies between 1 event (a smiley face projected on a screen) that was followed by a 2nd event (a complex picture projected on the other side of the screen). The results showed that early social contingencies are related to the competency to detect nonsocial action-consequence contingencies in the mobile conjugate reinforcement paradigm. (Contains 3 figures.)