Infants that are held less by caregivers show lasting changes to genes involved in immune response and metabolism, according to a study of children from British Columbia.
Fussy babies who were held the least were underdeveloped for their age in five areas of the genome when they were tested more than four years later. Fussy babies in the high cuddling range were normal.
The study also found a “vast” range in the time caregivers spent in contact with the babies, from 200 minutes a day up to about 1,400 minutes, said Michael Kobor, a professor of medical genetics and researcher for B.C. Children’s Hospital Research Institute.
The research involved 96 children who had initially participated as infants in research run by Ronald Barr at B.C. Children’s Hospital.
Parents did not receive instruction on how care for their children or whether to hold them, rather, they recorded the duration of contact as it occurred naturally.