. Little ones vary in the extent to which they enjoy the advantages of maternal delicate care or suffer the adverse implications of insensitive care, and these differences can be accounted for by biological features. However, how vulnerable small children adapt to maternal sensitivity in means that possibly maximize optimistic enhancement or lead to maladjustment has but to be determined. In this article, we propose a novel design of socioemotional mechanisms by which the joint influences of maternal sensitivity and kid biological features influence kid adjustment. Style and design . We propose a theoretical design, in which children’s vagal working and polymorphisms in serotonin transporter (5-HTTLPR) and dopamine receptor D4 (DRD4) genes confer susceptibility to the outcomes of maternal sensitivity on internalizing, externalizing, prosocial and moral conduct via alterations in interpersonal strategies for emotion regulation, the danger response process, and empathy. Results . Theoretical and empirical assistance for the proposed mechanisms are supplied. Conclusions . The proposed mechanistic design of susceptibility to maternal sensitivity delivers a novel framework of for whom and how small children are influenced by early maternal care, highlighting a number of reciprocal, interacting influences throughout genes, physiology, conduct, and the atmosphere.