Impact of Birth Order on Income: Firstborn Advantages Revealed

Research indicates that firstborn children may enjoy financial advantages over their younger siblings due to a combination of factors. These include receiving more attention from parents and unique experiences within the family setting. Recent studies show that older children often outperform their younger counterparts in academic assessments and tend to secure higher incomes in adulthood.

A new economic study, based on extensive data from Denmark, suggests that early childhood health issues can explain approximately 1.9% of the income disparity between siblings. Scholars at the University of Copenhagen discovered that health complications experienced in childhood could significantly influence later earnings. This aligns with findings from the University of Edinburgh, which indicated that firstborns generally possess higher Intelligence Quotient (IQ) scores—a difference that often manifests in the first year of life.

The study involved a comprehensive analysis conducted in partnership with a team from the University of Sydney, encompassing data from 5,000 children. These subjects underwent picture reading and vocabulary assessments biannually. Findings revealed that younger children are two to three times more susceptible to respiratory illnesses requiring hospitalisation. Children who frequently faced health issues during their formative years typically displayed poorer academic performance.

One hypothesis is that recurrent infections may divert developmental resources away from the brain, thus impacting cognitive growth. Given that kindergartens often serve as breeding grounds for common colds and viruses, older siblings frequently bring these infections home, potentially affecting the health of younger siblings.

Moreover, the disparity in parental attention is notable. Firstborn children often receive greater focus during their early years, while younger siblings may not benefit from the same level of individualized care, as parents manage increasing responsibilities with multiple children. Nutritionist Oksana Skytalinska discussed some of these themes in a recent episode of the podcast "What is it like to live?" where she explored lifestyle adjustments with age.