Attachment, exploration, and separation: illustrated by the behavior of one-year-olds in a strange situation.

The concepts of attachment and attachment behavior are considered from an ethological-evolutionary viewpoint. Attachment heliavior and exploration are viewed in balance, and the biological functions of each are discussed. As an illustration of these concepts, a study is reported of 56 white, middle-class infants, 49-~51 weeks of age, in a strange situation. The presence of the mother was found to encourage exploratory behavior, her absence to depress exploration and to heigJiten attachment behaviors. In separation episodes such behaviors as crying and search increased. In reunion episodes proximity-seeking and contact-maintaining behaviors were heightened. In a substantial proportion of Ss, contact-resisting behaviors were also heightened in the reunion episodes, usually in conjunction with contactmaintaining behaviors, thus suggesting ambivalence. Some Ss also displayed proximity-avoiding behavior in relation to the mother in the reunion episodes. These findings are discussed in the context of relevant observational, clinical, and experimental studies of human and nonhuman primates, including studies of mother-child separation. In conclusion, it is urged that the concepts of attachment and attachment behavior be kept broad enough to comprehend the spectrum of the findings of this range of studies.