The general proposition of attachment theory is that attachment is grounded in an independent, biologically based system. The quality of primary attachment relationships strongly influences a child's early personality organization, particularly the concept of self and others. The theory emphasizes the primary status and biological function of intimate emotional bonds between individuals. The theory postulates that intimate bonds are controlled biologically and use internal working models of the self and the attachment figure in relationship with each other. This doctoral research paper critiques recent research on attachment and discusses the implications of secure and insecure attachment of infants to their caregivers. Section 1 provides an overview of attachment theory. Section 2 critiques the methodology of attachment research and identifies common methodological problems. Particular attention is given to strange situation methodology and its alternatives. Section 3 reviews empirical literature that describes correlates of secure and insecure attachments in infancy. Discussion focuses on predictive hypotheses and correlates of secure attachment. A total of 53 references are cited. (RH)