This article first appeared on The Guardian, here.
The stereotype has long held that firstborn children go on to be bossy high flyers who leave their younger siblings behind. It’s a cliche some might dispute – from David Miliband, who watched his younger brother snatch the Labour leadership from under his nose, to Hilary du Pré, who saw her burgeoning musical talent eclipsed by her younger sister Jacqueline. Then there was Dante Gabriel Rossetti, who thought his poetry was good until Christina came along, and Jamie Murray, a star tennis player, who found himself outclassed by his little brother Andy.
But now a study suggests that the best efforts of the eldest child in a family can boost the performance of their younger brothers and sisters, in what the academics are calling the “sibling spillover effect”. Looking for the first time at how children from the same families get on at school, economists from the University of Essex found that the efforts of the oldest child did have an impact on how well their brothers and sisters got on in the classroom.
According to the research, having a big brother or sister is equivalent to £670 of school spending per year on the younger sibling’s score. The effect doubles if the siblings attend the same school. The researchers believe the results should be particularly interesting to policymakers on limited budgets tracking the progress of the Pupil Premium initiative, because the sibling spillover effect is even more pronounced in poorer families.
The study, by Birgitta Rabe and Prof Cheti Nicoletti for the Institute for Social and Economic Research at Essex, used data from the National Pupil Database, which covers the results of 93% of children through their time at state school. They looked at siblings’ key stage 2 test results and then their GCSE scores in 2007, 2008, 2009 and 2010.
It is the first study to look at the impact of siblings, rather than influence of parents, on exam results and the researchers took elaborate steps to factor out other considerations.
Rabe said: “How much a younger child’s school achievement is affected by their brother’s or sister’s achievement is a really important question to answer, as it helps us understand whether investments in children may have multiplier effects.
“We found that the sibling spillover effect is larger in families eligible for free school meals, living in deprived neighbourhoods and speaking a language other than English at home. This means that children from more deprived backgrounds benefit more from a high-attaining older sibling than children from more affluent backgrounds. It may be that the effect arises through information-sharing about educational choices and schools or teachers. Information on this is likely to be harder to come by in poorer families, and the benefit to younger children is therefore high.”
She said that the conclusion for policymakers had to be that it was even more worthwhile to invest in enhancing the progress of children from deprived families when it was clear that the impact of that investment would be multiplied for their younger siblings.
The achievements of big brothers and sisters can have a direct effect on the younger sibling’s school grades if the older one teaches the younger one or helps with homework; if the younger one imitates the older one, for example in their work style, or even, conversely, actually tries to be different, for example to avoid competition; and if the older one passes on important information about educational choices or schools and teachers to the younger child.
The researchers used mechanisms to rule out the similarities in results that might have been showing up because they come from the same family or go to the same school, in order to distinguish the direct influence of the older child on their younger sibling.
The study shows that there is a small but important direct effect from the older child’s test scores on the younger one’s exam grades. For each GCSE exam grade improvement of the older sibling – for example, from a B to an A – the younger sibling’s exam marks rise by 4% of a grade.
This effect is approximately equivalent to the impact of increasing yearly spending per pupil in the younger sibling’s school by £670. For poorer families this effect increases and even doubles in some cases, a finding which will be extremely interesting to policymakers looking to narrow the attainment gap between children from different socioeconomic classes. “Investing in the older child has pronounced results on their young brother or sister’s chances of success,” said Rabe. The news comes a little late, however, for David Miliband.