“…Since Ainsworth's seminal work on attachment security and maternal childrearing behaviors in her Uganda and Baltimore samples (Ainsworth, 1967;Ainsworth, Blehar, Waters, & Wall, 1978), parental sensitivity has been considered one of the most important determinants of individual differences in attachment security (Main, 1999). Observational and experimental studies of attachment have generally confirmed this idea, although the mean effect size for the association between parental sensitivity and attachment security is relatively modest (in De Wolff & Van IJzendoorn's, 1997, meta-analysis, the combined effect was r ϭ .24; see also Bakermans-Kranenburg, Van IJzendoorn, & Juffer, 2003).…”