Preschoolers' genetic, physiological, and behavioral sensitivity factors moderate links between parenting stress and child internalizing, externalizing, and sleep problems.

This study examined three potential moderators of the relations between maternal parenting stress and preschoolers' adjustment problems: a genetic polymorphism-the short allele of the serotonin transporter (5-HTTLPR, ss/sl allele) gene, a physiological indicator-children's baseline respiratory sinus arrhythmia (RSA), and a behavioral indicator-mothers' reports of children's negative emotionality. A total of 108 mothers (Mage  = 30.68 years, SDage  = 6.06) reported on their parenting stress as well as their preschoolers' (Mage  = 3.50 years, SDage  = 0.51, 61% boys) negative emotionality and internalizing, externalizing, and sleep problems. Results indicated that the genetic sensitivity variable functioned according to a differential susceptibility model; however, the results involving physiological and behavioral sensitivity factors were most consistent with a diathesis-stress framework. Implications for prevention and intervention efforts to counter the effects of parenting stress are discussed.