This is not doing my ego any good, but researchers at the University of Edinburgh have come forward to declare that first-born children are brighter than their younger siblings, and if IQ tests are anything to go by, then their findings, which are published in the Journal of Human Resources, are surely correct. The same researchers also believe that they know what causes what is known as the Birth Order Effect.
In their study, nearly 5,000 children were observed from pre-birth until the age of 14. Assessments, which factored in many variables, were conducted every two years. The researchers also took into account, things such as smoking, drinking, and etc.
In the end, they came to the conclusion that parental behavior is the most likely cause, pointing out that first born children tend to get far more attention during their early years compared to their younger siblings. Parents generally spend more time interacting with their first child during the early years than they do with their second or third child.