First-borns now have something to lord over their younger siblings: Being the eldest child may mean you're more intelligent than your younger brothers or sisters.
In a recent study by the University of Edinburgh, economists found first-born children received more mental stimulation in their early years, the Independent reports.
The study also notes first-born children were more likely to score higher on IQ tests since the age of one.
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 results? 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.
According to psychologist and New York University adjunct professor Ben Dattner, first-born children are more achievement-oriented and eager to please their parents. They are also more likely to take on leadership roles at work.
Older siblings also tend to follow the rules.
“First-borns tend to be responsible, competitive and conventional, whereas later-borns have to ‘distinguish’ themselves and create a specific niche by being playful, cooperative, and especially, rebellious,” Belgian psychologists Vassilis Saroglou and Laure Fiasse wrote in 2003.