This investigation considers the association between patterns of emotional reactivity and reliance on mother in infancy and cognitive and language developments at age 2. Low-income women (N = 518) and their firstborn infants participated in (1) a lab-based assessment where emotion challenges were presented when the infants were 6 to 9 months old, and (2) an assessment of language and cognitive skills at age 2. After controlling for birthweight, early sensorimotor delay, and age at testing, infants who displayed a pattern of combined high reactivity and high reliance on mother in response to positive, anger, and fear emotion challenges had higher cognitive and language skills at age 2 compared with infants who displayed patterns of low reactivity and low reliance on mother. Children who showed high fearful distress and low reliance on mother and whose mothers had low psychological resources had especially poor developmental outcomes. The role of maternal availability in the socialization of emotion and early communication is discussed.