This document provides data from an ongoing longitudinal study of the degree of continuity in individual development over time and describes the complexities involved in efforts to determine the nature of individual continuity. Findings from the Minnesota Longitudinal Study of children in a day camp provide evidence for continuity in individual adaptation, from infancy and the preschool years to middle childhood. Detailed observations of 16 children 10 years of age were conducted. Children with secure attachment histories were rated higher than insecurely attached children on ego-resiliency, self-confidence, and overall competence, and lower on dependency. Despite some promising results, the data do not adequately reflect children's developmental continuity. Two important keys to demonstrating continuity are having a sufficiently extensive data base at each time point, and having some degree of equivalency between the measures used. Four conceptual issues need to be resolved for an understanding of the nature of coherence in individual development: (1) behavioral organization becomes increasingly complex with development; (2) transformations can occur whereby an underlying structure is manifest in dramatically different ways; (3) a common developmental core may lead to branching pathways and multiple forms (that is, theoretically consistent but phenotypically dissimilar manifestations); (4) multiple routes may lead to the same basic outcome. (BN)