Developmental theories can be affirmed, challenged, and augmented by i
ncorporating knowledge about atypical ontogenesis. Because investigati
ons of human behavior are restricted by difficulties associated with c
ompromising the integrity of the individual's biological and psycholog
ical functioning, it becomes valuable to draw on the potential afforde
d by 'experiments of nature'. Examination of individuals with high-ris
k conditions and psychopathological disorders can provide an entree in
to the study of system organization, disorganization, and reorganizati
on. In this article, child maltreatment is examined to illustrate the
benefit that can be derived from the study of individuals subjected to
nonnormative caregiving experiences. The relevance of research on mal
treatment to several important aspects of developmental theory is exp
licated.