Passage Two

Regular child care provided outside home or by someone other than the mother does not in itself undermine(削弱) healthy emotional connections between mothers and their 15-month-old infants, according to a long-term national study. The finding holds even if care begins during the first 3 months after birth and runs for 30 hours or more per week. Among infants who receive unkind and unresponsive care from their mothers, however, the mother-child relationship may be damaged. "This research helps us put apart complexities regarding child care that have not previously been studied in detail." contends Jay Belsky, a psychologist at Pennsylvania State University. Belsky and several of his colleagues announced their findings last week at the international conference. The investigation consists of 1 153 children and their families living in or near Boston. The youngsters, no more than 1 month old when they entered the study in 1991, will be tracked until the age of 7. Experimenters administered questionnaires to mothers in their homes and videotaped baby caretakers interacting with the kids at ages 1, 6, and 15 months. Independent observers rated the quality of each child care efforts and noted infant nervousness. Unlike most previous studies, this one allows researchers to observe each caretaker’s personality at child nursing, and kids’ emotional reaction by the equipment. After taking family factors into account, other psychologists state that the researchers found no relation between the quality of child care and infants’ response. But the experimenters contend that the boys who spent more than 30 hours per week in child care exhibited more emotion for their mothers than other boys who didn’t, and the girls who spent the same hours per week in child care showed a modest rise in this emotion. Therefore, quality of child care outside home plays an important role in the connection between mothers and infants.

The main difference between the investigation and the previous ones is that ______.