The initial process of self development involves interaction with others and the establishment of relationships taking different paths depending on the socio-cultural context. Self-recognition and self-regulation are considered manifestations of this development between 18 and 24 months of age. This study aimed at analyzing the relationship between these two aspects, maternal beliefs about autonomy and relatedness, as well as identifying differences between boys and girls in this developmental stage. Participants were 94 mothers of different educational levels and their children of 17-22 months of age in two Brazilian cities. Socialization Goals Inventory and Parental Practices in the First Year Inventory were used to collect data on mothers' beliefs. Children performed tasks related to self-recognition (the mirror test) and self-regulation (compliance to requests). The group of mothers studied valued both autonomy and interdependence. Children's responses are consistent with a perspective of relational autonomy, which value both independence and interdependence. Differences were found in relation to sex in both self-recognition and self-regulation, and baby girls showed superior performance than boys in both tasks.