Belsky & Rovine (1988)

Data from 2 longitudinal studies of infant and family development were combined and analyzed

149 infants (90 males)

Ages 12 and 13 months

20 or more hours of care per week

Working class and middle class SES

Married parents

Interviews

Strange Situation

1. Infants exposed to 20 or more hours of care per week were more likely to be classified as insecurely attached to the mother and to avoid the mother on reunion than were infants in care fewer than 20 hours per week.

Lamb, Sternberg, & Prodromidis (1992)

Data from 13 studies were combined and analyzed

897 infants (493 males) and their mothers

Ages 11 to 24 months

Mothers averaged 32.6 hours of paid work per week

Strange Situation

1. Secure attachments were significantly more common among infants in exclusive maternal care.

2. Insecure attachments were significantly more common among those infants assessed after 15 months of age and among those who entered care between 7 and 12 months of age, rather than before.

3. Extent of nonmaternal care was not significantly associated with attachment classifications.

NICHD Early Child Care Research Network (1997)

1,153 mothers and their babies chosen from among 31 hospitals in 9 states

24% ethnic minority

14% single mothers

Assessment of Infant Security Attachment

Strange Situation

Attitude toward Maternal Employment Questionnaire

Infant Temperament Questionnaire

NEO Personality Inventory

Center for Epidemiological Studies Depression Scale

Infant Toddler HOME Scale

Observational Record of the Caregiving Environment

1. Use of non-maternal care did not make a significant difference in children's attachment security.

2. Infants were less likely to be secure when low maternal sensitivity/responsiveness was combined with poor-quality child care, more than minimal amounts of child care, or more than one care arrangement.

3. Boys who were in many hours of care and girls who were in minimal hours of care were somewhat less likely to be securely attached.