The absence of typical caregiving, including warm and responsive parenting, has been suggested to significantly affect the young child's ability to form adaptive relationships with adults and peers. The Bucharest Early Intervention Project (BEIP), a randomized controlled trial of foster/family care for young children with a history of institutionalization has provided the context to assess these relationships. Here we review data from the BEIP with specific focus on attachment. The findings clearly show the importance of early family care on the emergence of attachment, on the prevention of psychopathology, and on links between brain and social behavior.