More than two decades after adoption: Associations between infant attachment, early maternal sensitivity and the diurnal cortisol curve of adopted young adults

The focus of this study was on the longitudinal relation between infant attachment, early maternal sensitivity and the diurnal cortisol curve of adopted young adults. 86 adoptees (mean age at adoption 11 weeks) were followed from infancy to young adulthood. Attachment quality and maternal sensitivity were observed in infancy. When the adoptees were 23 years of age saliva samples were collected at six time points across the day, on two different days. To assess compliance to the instruction the Medication Event Monitoring System (MEMS) was used. The data were analyzed with growth models using multilevel analyses (Day 1) and structural equation modeling (as a more confirmatory approach, Day 2). Results revealed no associations between early attachment security, attachment disorganization, maternal sensitivity and the diurnal cortisol curve more than two decades later. Attachment experiences (in the normative range) may not induce changes in the later diurnal cortisol curve in the same way as severe chronic stressors do. Alternatively, adoption related experiences may dampen associations between attachment experiences and the diurnal cortisol curve in later life.