Data from 2 separate projects were examined to address the stability o
f infant-parent attachment security. Both included infant-mother attac
hment classifications at 12 and 18 months of age (n = 125, n = 90), an
d 1 included infant-father classifications at 13 and 20 months (n = 12
0). Significant stability was not discerned in attachment security, ei
ther at the level of ABC or secure-insecure classifications. Rates of
stability ranged from 46-55%. Results are discussed in terms of the se
lect nature of the samples studied (all sons in 1, some depressed moth
ers in the other), the fact that past estimates of stability are based
on small samples, the potential influence that coding for disorganize
d behavior may have on how Strange Situations are classified, and the
changing ecology of infancy over the past 10-15 years.