Work in developmental psychiatry and psychology has increasingly focused on how internal representations of early experiences with primary figures of childhood affect relationship formation in later childhood and adulthood. Investigations of the reflective self function, which involves mental states in which individuals become the subject of their own thought, have demonstrated that individuals' capacity for using mental state constructs in discussing attachment relationships in Adult Attachment Interview protocols captures differences in individuals' sensitivity. Ratings of the reflective self function of parents before the birth of their child have predicted the nature of the later relationship between infant and parent. This predictive ability may be of practical use. Severe borderline states may be understood as involving dysfunctions of reflective self processes. In an ongoing study, interviews with borderline patients suggest that individuals who respond to childhood experiences of maltreatment by an inhibition of reflective self function are less likely to resolve this abuse, and are more likely to manifest borderline psychopathology than individuals who respond in other ways. The importance of reflective self function for attachment is greatest when the hardship suffered by individuals places them, when they become parents, at risk of recreating these negative experiences in their children. A list of 71 references is included. (MM)