“Our main question was simple,” says Vacaru. “We wanted to know whether the quality of parent–child interactions during the foundational developmental years is linked to children’s long-term health. Not just their psychological wellbeing, which we already have compelling evidence for, but also their physical health.”
Following families for 14 years
The study is part of the Nijmegen-based BIBO cohort, a unique project that has followed children and parents from pregnancy into young adulthood. “In this study, we observed mothers and babies as early as five weeks after birth,” Vacaru explains. “Researchers visited families at home and looked at very natural caregiving tasks, like changing a diaper or a bath. We repeated parent-child observations at ages 1, 2.5, 10, and 14 years, to examine parental sensitivity to the child. At 12 months, infant-mother attachment security was evaluated through laboratory observations of how infants responded to brief separations and reunions with their mothers. Additionally, they had monthly interviews with parents in the first year of life and after with intervals of 1-2 years, to learn about children’s health.”
The results were striking. Children of mothers who were more sensitive to their needs showed significantly fewer health problems up to age 14. “The effects were particularly strong for respiratory complaints, like coughs and breathing difficulties, and for digestive issues,” says Vacaru.
More than basic care
Importantly, the study investigated variations in the quality of caregiving, beyond instrumental care. “It’s about tuning into the baby’s signals,” Vacaru explains. “For example, giving the child time to adjust, mirroring their expressions, or responding to their bids for comfort. These small differences in sensitivity matter a lot in shaping children’s wellbeing.”
The researchers think one explanation could be stress regulation. “When children feel understood and supported, they learn to regulate stress better. And that can have long-term effects on the body,” says Vacaru.
Team Science
For their interdisciplinary work, the BIBO team was awarded the Radboud Team Science Award of 2025. According to the jury, Team BIBO has managed to actively maintain and manage a unique longitudinal dataset for nineteen years through joint efforts. The jury found it remarkable that the team has managed to retain 80% of the original participants over such a long period. The team also makes its rich dataset available to researchers worldwide, actively contributing to Open Science.
