Stress in various environments and situations are significant predictors of childhood externalizing behaviors according to several research studies. Commonly, family environmental stress is correlated with externalizing behaviors in children. Studies found significant relationships between childhood externalizing behaviors and environmental hinderances to learning, prenatal exposure to methadone in mothers, and exposure to chronic maternal depression. Marital adjustment and lack of warmth in adoptive homes also predicted externalizing behaviors. Admission to in-patient psychiatric treatment was another significant predictor of externalizing behaviors in children.