Being the eldest child may mean you're more intelligent than your younger brothers or sisters.
Economists at the University of Edinburgh have concluded that first-borns have a higher IQ test score than their siblings as early as age one
Researchers said the findings could be explained by first-born children receiving more mental stimulation and support in developing thinking skills from their parents during their early years.
Researchers worked with Sydney University and examined data from 5,000 children. Each child was given a reading and picture vocabulary test every two years.
The tests included reading recognition, such as matching letters, naming names and reading single words aloud.
First-born children were more likely challenged intellectually at a younger age, therefore, scoring higher on these tests.
And although younger siblings got the same type of emotional support from their parents, it turns out parents spent less time on brain-stimulating activities with younger siblings, which could include music, reading and crafts.
Previous studies have also found similar results. And some other find the older siblings also tend to follow the rules.