The rumours have been mulling around for years. Does birth order really matter when it comes to intelligence? Well we’ve found scientific evidence to finally give you a concrete answer.
A study by researchers at the University of Edinburgh shows that first-born children do in fact have a higher IQ than their younger siblings. And apparently their parents are to blame.
Scientists found that the lower IQ in younger siblings could be down to differences in parental attention. While older siblings are likely to have spent focused alone time with their parents being mentally stimulated through reading, creative activities and playing musical instruments before the second child was born, younger siblings are accustomed to sharing their time with another child, without that focused attention the older brother or sister would have had.
This could help to justify the impression that birth order leads to higher wages and better education in first-borns.
The study, published in the Journal of Human Resources and carried out in partnership with Analysis Group and the University of Sydney, looked at data from the US Children of the National Longitudinal Survey of Youth collected by the US Bureau of Labour Statistics to come to their conclusions.
The study examined almost 5,000 children from before birth up until 14 years of age. They assessed skills, such as reading and picture vocabulary, every two years to gauge the differences between first-borns and younger siblings.
Researchers also looked at children’s test scores in relation to parental behaviour, like smoking and drinking during pregnancy. They found that mothers tended to be more careful during their first pregnancies and were likely to take ‘higher risks’ during subsequent pregnancies. While this was not directly related to the study results, it could have a bearing on children’s IQ levels.
But while younger siblings can blame parents for possibly offering less support in developing thinking skills during their formative years, this study doesn’t give them an excuse to grill you about that one glass of wine you had during your third trimester!