Attachment theory is the joint work of John Bowlby and Mary Ainsworth (Ainsworth & Bowlby, 1991). Drawing on concepts from ethology, cybernetics, information processing, developmental psychology and psychoanalysis, John Bowlby formulated the basic principles of the theory. It thus revolutionized our thinking on the child's bond with the mother and its rupture through separation, deprivation and mourning. Mary Ainsworth's innovative methodology not only allowed some of Bowlby's ideas to be tested empirically, but also helped to expand the theory itself and is responsible for some of the new directions it takes today. Ainsworth contributed to the concept of the attachment figure as a secure base from which an infant can explore the world. Additionally, she formulated the concept of maternal sensitivity to infant cues and its role in the development of infant-mother attachment patterns (Bretherton, 1985). Bowlby's main conclusion, based on the available empirical evidence, was that to grow up mentally healthy, "the infant and young child should experience a warm, intimate, continuing relationship with his or her mother (or permanent substitute mother) in which both find satisfaction and pleasure” (Bowlby, 1951). Relationship-based learning evolves from the constructs of attachment theory. In typical early childhood development, relational experiences between the infant and mother (or primary caregiver) are meaningful for survival and facilitate the infant's exploration of the world. During these early experiences, caregivers engage in a sensitive, reciprocal, synchronous, and empathetic response to their baby. These ongoing and adaptive interactions lead to secure attachment (Bowlby, 1969, 1988). Research has shown that positive results...... middle of article ......ademic Press.Mahoney,G. (1991). Responsive parenting: A relational model for early intervention. Paper presented at the Gulf States Conference on Early Intervention, Point Clear, AL.McLeod, SA (2008). Mary Ainsworth | Attachment styles. Retrieved from http://www.simplypsychology.org/mary-ainsworth.html Siegel, D. (1999). The developing mind: toward a neurobiology of interpersonal experience. New York, Guilford Publications. Tizard, B. and Joseph, A. (1970). Cognitive development of young children in residential care: a study of children aged 24 months. Journal of Child Psychology and Psychiatry, 11: 177-186. Wetherby, AM, Prizant, BM, & Schuler, AL (1997). Improving language and communication: theoretical foundations. In D. Cohen & F. Volkmar (Eds.), Handbook of autism and pervasive developmental disorders (2nd ed...)