Individual differences in infant-mother attachment at twelve and eighteen months: stability and change in families under stress.Child Dev. 1979 Dec; 50(4):971-5.CD
100 economically disadvantaged mothers and their infants were observed in the Ainsworth and Wittig "strange situation" at 12 and 18 months. Infants were classified as secure, anxiously attached/avoidant, or anxiously attached/resistant. In addition, mothers reported occurrence of stressful events related to the stability of the caretaking environment during the 12--18 month period by completing a 44-item checklist concerning work, finances, family, neighbors, health, etc. 62 infants were assigned to the same attachment classification at both 12 and 18 months (p less than .01). Despite this stability, significantly more infants changes classification than in a recent study of stable middle-class families. With the present sample, anxious attachment was associated with less stable caretaking environments than secure attachment; change from secure to anxious attachment was associated with higher stressful-event scores than stable secure attachment.