After much debate between siblings over who is the smartest of the lot, it has finally been confirmed that the first-born child is smarter than the middle, or youngest sibling.
Research carried out at the University of Edinburgh revealed that first-born children have superior thinking skills compared to their younger siblings.
This is because they receive more mental stimulation from their parents, according to the study, which was published in the Journal of Human Resources.
The research involved assessing roughly 5,000 children from pre-birth to 14 years of age, with children assessed every two years.
Tests involved reading recognition, including matching letters, naming names and reading single words aloud and picture vocabulary assessments.
Although the study found that parents give their children equal amounts of emotional support, the first-born generally received more help with tasks that develop thinking skills.
The study stated: "First borns score higher than their siblings in IQ tests as early as age one."
The researchers found that parents changed their behaviour as subsequent children were born, offering less mental stimulation to younger siblings.
Mothers also took higher risks during the pregnancy as more children were born, such as increased smoking.
We can sense all of the middle and youngest siblings around the country bursting with rage...