This report aimed to investigate the capacity of maternal behaviors tailored to children's attachment and exploration systems to jointly explain the well‐known mother–child transmission of attachment. Four home visits were conducted between ages 7 months and 2 years with 130 mother–child dyads to assess maternal attachment state of mind, sensitivity, autonomy support, and mother–child attachment security. Results showed that together, maternal sensitivity and autonomy support fully accounted for the relation between maternal and child attachment, that they each accounted for a unique portion of this relation, and that the magnitude of these mediated pathways was equivalent. These results suggest that the attachment transmission gap can be narrowed by the use of a theory‐driven multidimensional approach to maternal behavior.