Intergenerational transfer effects describe the transmission of traits, skills, or biology from parents to their offspring. Through genetic and environmental influences parents, for example, impact their children’s ability for perspective-taking (i.e., mentalizing), which is linked to an individuals’ healthy social functioning. Mentalizing is supported by a network of brain regions, including bilateral temporoparietal junction, precuneus, and prefrontal cortex. The neural correlates reflecting on parent-child similarity have yet to be studied. Here, we describe task-based functional connectivity (FC) strength during mentalizing and test dyadic similarity in 76 healthy parent-child dyads (81 children:6-14y, 29 girls; 74 parents, 58 mothers). Children and adults’ group-wise ROI-to-ROI FC (FDR-corrected) and average network strength were computed. Next, familial mother-child and non-familial adult-child brain similarity was calculated. Familial and non-familial adult-child similarity was compared using cocor, testing whether similarity was specific for biologically related dyads. Significant FC similarity was inferred using a Fisher’s combined probability test in familial (X2(152,N=76)=777.14, p<.001) and non-familial dyads (X2(9244, N=4622)=46969, p<.001). Familial specificity was not confirmed. With age, FC similarity between female children and their parents significantly increased (r=.36,p=0.04; Fig.1B), possibly reflecting an earlier network development in girls. Overall, the mentalizing network strength in children (r=.33) was significantly weaker than in adults (r=.42,p=<.01; Fig.1A), which is likely due to ongoing maturation in the children’s group. Future analyses will focus on connections of interest (e.g., long-range connections) and test whether child-to-child FC similarity exhibits more variability than adult-to-adult FC similarity, due to ongoing developmental changes in the children’s group.