Abstract
Attachment theory (Bowlby, 1973, 1980, 1969/1982) suggests that early interpersonal experiences lay the foundation for the ways people think, feel, and behave in close relationships throughout life. The present study examined this fundamental assumption, analyzing longitudinal data collected from 705 participants and their families over 3 decades, from the time participants were infants until they were approximately 30 years old (M(age) = 28.6, SD = 1.2; 78.7% White, non-Hispanic, 53.6% female, 46.4% male). We examined the associations between early levels and growth (or changes) in the quality of people's close relationships during childhood-including with their parents, friends, peers, and romantic partners-and their attachment orientations in adulthood. The findings suggest that early experiences with caregivers play a foundational and enduring role in people's attachment-related functioning: Early levels of mother-child relationship quality predicted individual differences in general attachment anxiety and avoidance in adulthood, as well as adults' relationship-specific attachment orientations in each of their close relationships, including with their mothers, fathers, romantic partners, and best friends (median R² = 3% for attachment anxiety and avoidance across relationship domains). Early levels and growth in the quality of people's friendships during childhood also predicted general attachment orientations in adulthood (R²(attachment anxiety) = 2%; R²(avoidance) = 9%) and played a particularly important role in guiding the ways adults tended to think, feel, and behave in their friendships and romantic relationships (R²(attachment anxiety) = 4%; R²(avoidance) = 10%-11%). (PsycInfo Database Record (c) 2026 APA, all rights reserved).