The purpose of this longitudinal study was to contrast the maternal care of two groups of middle-class American mothers and to assess the effect of these different patterns of maternal care on infant development. Sixteen of the mothers involved in the study were selected because of their commitment to the La Leche style of maternal care, which emphasizes the benefits of breast feeding, late weaning, and frequent infant-mother physical contact. A comparison group of 16 mothers who nursed their infants, but did not belong to the La Leche League, also participated in the study. Researchers visited the families at their homes eight times over a period of two years when the baby was 2, 4, 7, 10, 13, 16, 20, and 24 months old. At each home visit there were brief interviews in which data on family's overall health, infant's sleeping patterns, introduction of supplementary food, weaning age, and resumption of mother's menstrual cycle were collected. There were also 90 minutes of observation of mother-infant interaction at each home visit. Mothers recorded breast feeding frequency and duration on time lines in a diary for one 24-hour period at each of the above eight age points. Extensive home interviews were conducted with the mothers at 6 weeks, 13 months, and 24 months. A videotape of three minutes of face-to-face interaction between mother and infant was also made during a home visit. Additionally, a Rothbart Infant Behavior Questionnaire to assess temperament was filled out at home by the mother at 9 months, and testing to assess language development and vocabulary wascompleted at home at 20 months. There were five laboratory visits to assess infant motor and mental development. Bayley Scales of Infant Development were administered at 10 and 24 months, and Kagan cognitive tests (also called draw-a-face tests) at 22 months. During the laboratory visits, videotapes were made of the Ainsworth Strange Situation procedure at 12 and 22 months, and of the interaction of the infant with an unfamiliar peer at 23 months. The Murray Center holds a computer tape of coded interactions, videotapes, and raw data from this study.
