Impact trajectories of childhood maltreatment duration on affective and social development.

Childhood maltreatment (CM) deeply impacts victims' social competences. The aim of the present study was to investigate the effect that CM duration exerts on victims' affective and social development testing three different impact trajectories (i.e., linear, logarithmic and quadratic) and its physiological (facial mimicry and autonomic regulation of the heart) and behavioral (percentage of anger recognition false alarm) markers. In a cross-sectional design, 73 Sierra Leonean youths (all males, 5-17 years old) were enrolled in the study. Of those, 36 were homeless all abandoned at the age of 4 and exposed to CM, whereas 37 were controls. Only physiological markers of affective development were influenced by CM duration. A quadratic relation between the autonomic regulation recorded at rest and CM duration was found, indicating initial physiological compensation followed by progressive autonomic withdrawal. Furthermore, CM duration was associated to a specific linear decrease of facial mimicry and vagal regulation in response to angry and sad facial expressions whereas no influences were detected for happy and fearful faces. The results of the present study provide insightful clues on victims' natural patterns of resilience, deterioration, and chronicity, allowing a deeper comprehension of the developmental pathways through which early life adversities place youths on a track of lifelong health disparities.