Parents’ comparisons widen sibling differences, study says

The expectations parents have for their children could make a huge difference when it comes to sibling performance, particularly in academics.

That’s according to a new study that found the way parents compare their children to one another really does shape the differences between brothers and sisters.

“Parents’ beliefs about their children, not just their actual parenting, may influence who their children become,” said study author and professor Alex Johnson in a release.

For the study, published this month in the Journal of Family Psychology, researchers talked to parents of 388 teenagers, specifically about their first- and second-born children. They asked the parents — all of whom live in the northeast — to identify which of their children performed better academically.

While the majority of parents said their oldest child was best in school, in reality, researchers didn’t find much of a difference in grades and test scores.

“A mom or dad may think that oldest sibling is smarter because at any given time they are doing more complicated subjects in school,” said Jensen. “The firstborn likely learned to read first, to write first, and that places the thought in the parents’ mind that they are more capable, but when the siblings are teenagers it leads to the siblings becoming more different.”

Interestingly enough, beliefs parents held about the differences in their children influenced their teenagers future grades, researchers said. The child deemed “smarter” performed better in school, while the other sibling fell behind in the next school year.

“Ultimately, the sibling who is seen as less smart will tend to do worse in comparison to their sibling,” Jensen said.

The beliefs of their parents translated to a GPA difference of .21, according to the study.

“That may not sound like much, but over time those small effects have the potential to turn into siblings who are quite different from one another,” said Jensen.

The only exception to the rule identified by the study: If a firstborn happened to a brother with a younger sister, parents often identified the younger sister as the smarter child.

“Parents also tend to think their daughters are more academically competent than their sons, and at least in terms of grades that seems to be true,” Jensen said.

Researchers said it’s important for parents to watch what they say about their children in front of their children — particularly when it comes to differences.“To help all children succeed, parents should focus on recognizing the strengths of each of their children and be careful about vocally making comparisons in front of them,” researchers say.