London, First-born kids really are smarter than their younger siblings, a new study found.
The main reason there is a disparity between progeny is that moms and dads parent their kids differently. In general, they spend more time teaching their oldest child how to think and problem-solve while they take greater risks with subsequent offspring.
As a result, the first-born child in a family ends up having a higher IQ than their siblings, a difference which shows up as early as age 1, according to The Telegraph.
The startling conclusion comes from researchers at Edinburgh University who looked at more than 5,000 children. Using data from the US children of the National Longitudinal Survey of Youth, a dataset collected by the US Bureau of Labor Statistics, the researchers looked at IQ test results gathered every two years from pre-birth to age 14.
After controlling for socio-economic factors and family background, the researchers found that first-born children, starting at age 1, were demonstrably better than their younger siblings in reading, math, verbal communication and general awareness.
"As the household gets bigger, time has to be split with younger children so they miss out on the advantage of being an only child for a time," Dr. Ana Nuevo-Chiquero said.
"It doesn't mean first-borns get more love, that stays the same. But they get more attention, especially in those important formative years".
According to Nuevo-Chiquero, her team's findings might explain the so-called "birth order effect" whereby older siblings have been observed to do better in both school and in their careers than their younger siblings.
Source: Qatar News Agency