Topic > John Bowlby's attachment theory and the internal working model (IWM) are synthesized to explain how a child's personality begins to develop during the early stages of his or her life. Infants actively seek out interaction, and it is the nature, consistency and sensitivity of the mother's response to the infant's attachment that determines the development of IWM, this is known as reciprocal interchange (Schore, 2000; Ainsworth & Bowlby , 1991). How the IWM develops will therefore determine the attachment style the child has with the mother and, ultimately, what personality traits he or she will begin to develop..