A new award winning study conducted at Oxford University challenges the widely believed idea that a child with more siblings gets less parental attention and so does worse in tests of literacy and maths.
Many researchers have compared families with many children to families with few, finding a consistent tendency for children with fewer siblings, and siblings further apart in age, to do better. But are we simply seeing a tendency for better-educated and wealthier parents to have fewer children? And does the investment by parents fall with a new addition to the family, or does it just change in nature?
Dr Joseph Workman looked at 2- to 4-year-old children in the same families before and after a younger brother or sister was born, to see what impact adding a sibling would have. He used data from a large study tracking 10,700 American children born in 2001, the Early Childhood Longitudinal Study – Birth Cohort (ECLS-B).
He also lifted the lid on the different things in a family that are affected by the addition of a sibling. He looked at resources (Is there enough food? How much do parents read to the child? Do they use outside childcare? Do the parents go out to play with the child?). He looked at the mother’s mental health, the parent-child relationship and the number of children’s books in the house.
Contrary to other studies, he found that the addition of a sibling any time under the age of 5didn’t reduce a child’s cognitive development on average. This was true irrespective of family income, race/ethnicity and practice of religion.
It’s true that adding of a sibling reduced the measured time that parents spent reading stories and the amount of childcare the family used (something considered to be positive for cognitive development). However, the declines in the quality of children’s home experiences were not substantial enough to reduce children’s cognitive development.
Dr Workman asks: Could it be that the addition of a sibling doesn’t actually decrease parents’ investment in each child, but rather changes it from an individual activity to a communal one? If so, then current measures of parental investment that look only at individual contributions may be misleading.
Workman J, Sibling additions, resource dilution, and cognitive development during early childhood, Journal of Marriage & Family, forthcoming (2016)