This paper describes the design of the interdisciplinary study of the growth and development of Dutch children in progress at the University of Nymegen, The Netherlands. Schaie's design is based on a trifactorial model which isolates the contributions to developmental data of the factors age, cohort and time of measurement. (Author/MS)

Considers evidence for continuity and discontinuity of attachment in four major longitudinal studies. Discusses the difficulty of constructing a critical test of the prototype and stable environment hypotheses for attachment continuity. Notes that intergenerational transmission of attachment has been only indirectly addressed. (KDFB)