This first volume of John Bowlby's Attachment and Loss series examines the nature of the child's ties to the mother. Beginning with a discussion of instinctive behavior, its causation, functioning, and ontogeny, Bowlby proceeds to a theoretical formulation of attachment behavior—how it develops, how it is maintained, what functions it fulfills. In the fifteen years since Attachment was first published, there have been major developments in both theoretical discussion and empirical research on attachment. The second edition, with two wholly new chapters and substantial revisions, incorporates these developments and assesses their importance to attachment theory.