This study compared the development of 38 infants from separated or divorced families with that of 38 infants from married families in Britain to determine whether parental divorce or separation precipitates cognitive, social, or emotional difficulties in infants. Infants were 11 to 45 months old. Infant-mother attachment was measured using the traditional strange situation laboratory procedure, and infant cognitive development was assessed using the Griffiths Scales of Mental Development. Infants with older siblings were observed interacting with their siblings at home for a 1-hour period on two occasions. Mothers completed the Infant Characteristics Questionnaire to assess infant temperament. Mothers also completed the Parenting Stress Index and the Life Events Survey, and were interviewed about their parenting experiences. Contrary to American studies, results from this study revealed more similarities than differences between the two groups. No differences in security of attachment, sibling relationships, temperament, or cognitive ability were found. Such patterns were found in spite of the fact that separated or divorced mothers experienced more stress than their married counterparts. Findings suggest that marital separation does not necessarily lead to child problems. (MM)