Attachment theory, researched by John Bowlby and others, has continued to deepen our understanding of early object relationships. While a different strain of psychoanalytic theory and research, the findings in attachment studies have continued to support the validity of the developmental progressions described in object relations. Recent decades in developmental psychological research, for example on the onset of a "theory of mind" in children, has suggested that the formation of the mental world is enabled by the infant-parent interpersonal interaction which was the main thesis of British object-relations tradition
(e.g. Fairbairn, 1952).