Great news if you're the oldest sibling in the family - a recent study from the University of Edinburgh found that first-born children were smarter than their younger brothers or sisters. First-born children received more mental stimulation from their parents during early stages of development, experts concluded. "Researchers found that parents changed their behavior as subsequent children were born," the University of Edinburgh said Thursday. "They offered less mental stimulation to younger siblings, and also took part in fewer activities such as such as reading with the child, crafts and playing musical instruments." First-born children scored higher than their younger siblings on IQ tests, even at the age of one. Scientists say the discovery could explain the "birth order effect," when children born earlier in families reported higher wages and education levels later in life. Economists from the University of Edinburgh, the Analysis Group and the University of Sydney closely reviewed data from the US Bureau of Labor Statistics. More than 5,000 children were monitored from pre-birth to age 14, each undergoing assessments every two years. Tests included "reading recognition, such as matching letters, naming names and reading single words aloud and picture vocabulary assessments." The advantages of first-born siblings began at birth to three years of age, according to the study.