On this page
"Your sister never needed reminding to study." Parents usually mean this as a nudge. Children tend to hear a ranking, and research suggests rankings at home can shape how each child performs and feels.
What does research say about comparing siblings?
The clearest evidence comes from a study that followed 388 families over three years, by Alexander Jensen and Susan McHale, published in the Journal of Family Psychology in 2015. Mothers and fathers rated how their two children, an older sibling of about 15 and a younger one of about 13 at the start, differed in academic ability, and the researchers tracked both children's grades. After accounting for earlier grades, the child parents saw as more competent earned relatively higher grades the following year. The reverse did not hold: differences in grades did not predict a change in parents' beliefs. And the sibling with better grades went on to report stronger academic interests than the other.
That is a correlation in one population, not proof that a single comment changes a report card. But it fits a wider pattern. A study of 516 two-child families by Feinberg and colleagues (Child Development, 2000) found evidence that adolescents compare how parents treat them with how their sibling is treated, and that self-esteem and emotional temperament affected how they judged those differences.
The effect does not disappear when children grow up. In a study of 151 pairs of young adult siblings, Jensen, Whiteman, Fingerman and Birditt (2013) found that the sibling who reported getting less support than the other reported more depressive symptoms, and bigger differences in treatment went with less closeness between siblings.
Why comparison backfires
Comparison gives a child information about their position, not about their work. "Your brother got 92" tells a 15-year-old nothing about why their own physics answer went wrong, but it tells them who is winning. Three things tend to follow:
Roles harden. One child becomes "the maths one", the other "the creative one". Each starts avoiding the other's territory.
The sibling becomes a rival. Help between them dries up just when an older sibling's notes or explanations could be most useful.
Effort goes into protecting the label. The "smart" child may avoid hard problems so the label is not tested; the other may stop trying because the slot is taken.
What to say instead: a swap list
Each line below keeps the expectation but removes the ranking.
Instead of "Why can't you be organised like your sister?", try "Your chemistry notes are spread across three notebooks. Want to pick one place for them tonight?"
Instead of "Your brother cleared JEE Main on his first attempt", try "What did the last mock show you about which chapters need time?"
Instead of "She never needed tuition", try "What kind of help would be useful this month: a teacher, a study group, or just a quieter room?"
Instead of "You are the clever one, you will be fine", try "You worked through every exercise in that chapter. That is why it went well."
Instead of "Look at your cousin's rank", try "What is one thing you want to be better at by the next test?"
The pattern: describe the specific work, ask a question the child can answer, and leave the sibling out. This matches what research on helping children learn without pressure finds about praise for process rather than labels.
How to handle the comparisons children make themselves
Siblings will compare marks whether you do or not. When one child says "I am the stupid one", resist reassurance by ranking ("No, you are just as smart as him"). Try this three-step reply instead:
Name the feeling. "It sounds frustrating to see his result next to yours."
Separate the subjects. "He is in Class 12 with two more years of practice. You are learning this chapter for the first time."
Move to a next step. "Which question type cost you the most marks? Let's look at one."
For the older sibling, give a role that is not "the example". Asking them to explain a concept to a younger sibling, once in a while and only if both want to, turns a rivalry into teaching, which can help the explainer too.
A one-week check for parents
For a week, note each time you mention one child while talking to the other about studies. Pick the two most frequent phrases and write their replacements from the swap list on a sticky note. If your children share a study space, our guide to setting up a good study space at home covers how to give each child their own corner and routine.
When a younger child is stuck on a concept an older sibling "just got", the gap is usually a missing building block, not ability. The Fermi Concept Library has a lesson for each concept in physics, chemistry, biology and mathematics, so a child can go back to the missing piece on their own, without anyone comparing.
