Babies who spent more than one night a week away from mother are 'more insecure' Claiming the study is importnat because of the growing number of parents living apart, she said the study raised the question: 'Would babies be better off spending their overnights with a single caregiver, or at least less frequently in another home?' She pointed out that either the mother or father could be the primary caregiver, but the point would be that the child ideally would be in the care each night of a loving and attentive caregiver and that there may be something disruptive about an infant spending nights in different homes. Ms Tornello added: "We would want a child to be attached to both parents, but in the case of separation a child should have at least one good secure attachment. It's about having constant caregivers that's important. Along with co-authors, including psychology Professor Robert Emery, she analysed data from the Fragile Families and Child Well-being Study of about 5,000 children born in large U.S. cities from 1998 to 2000. The data consisted of interviews with both parents at the time of the child's birth, and at ages one and three. Additional in-home assessments of the children were conducted when they were one and three. Of parents who were not cohabiting at the time of the study, 6.9 per cent of babies under the age of one and who lived primarily with their mother spent at least one overnight a week away with their father. Among toddlers ages one to three, 5.3 per cent spent between one per cent and 35 per cent of overnights away with their fathers. Another 6.8 per cent spent 35 per cent to 70 per cent of overnights with their fathers. Infants who spent at least one overnight a week away from their mothers were discovered to have more insecure attachments to them compared to babies who had fewer overnights or stayed with their father only during the day. A total of 43 per cent of babies with weekly overnights were insecurely attached to their mothers, compared to 16 per cent with less frequent overnights. In the case of toddlers the findings were less dramatic; greater attachment insecurity was linked to more frequent overnights, but the findings there were not statistically reliable, said Ms Tornello. Prof Emery, Ms Tornello's research adviser, said: "I would like infants and toddlers to be securely attached to two parents, but I am more worried about them being securely attached to zero parents." He advocates parenting plans that evolve, where day contact with fathers occurs frequently and regularly, and overnights away from the primary caregiver are minimised in the early years, then are gradually increased to perhaps become equal in the pre-school years. He added: "If mothers and fathers can be patient, cooperate and take a long view of child development, such evolving plans can work for both children and parents." The finding were published in the Journal of Marriage and Family.