This paper highlights the results of two research studies, the first of adults who experienced separation and divorce prior to their 14th birthday, and the second, a preliminary observational study of infants and toddlers whose parenting time with their second parent included day visits and overnights. There are striking parallels between these populations when reviewing the adverse effects of separation and divorce. The preverbal behaviors of the infant and toddler group are precursors of the effects reported by adult children of divorce that include states of missing, sadness, and loneliness; instability regarding a sense of home; and difficulty establishing both an integrated sense of self and self-constancy.