Researchers studying 10.3 million US children link birth order to health
It turns out, whether you are the oldest or second in your family might actually affect your health.
A massive new study from University of Chicago and Columbia University looked at US health insurance data covering more than 10.3 million kids with one sibling in the US and found first-born children are more likely to develop conditions like autism, ADHD, Tourette syndrome, OCD, and allergies.
Second-borns, meanwhile, tend to face more digestive issues, migraines, shingles, and substance use disorders.
Birth order linked to 150 conditions
Researchers spotted birth order differences across 150 diseases.
First-borns showed higher rates of neuropsychiatric conditions; second-borns had more digestive and musculoskeletal problems.
Interestingly, bigger age gaps between siblings raised autism risk for first-borns but lowered allergy differences.
The team says biological and social factors probably play a role here, and they hope future studies will dig deeper into why birth order matters for our health.