Firstborn Children Are Actually Smarter Than Their Siblings, According To Science

Firstborns are more intelligent than their younger siblings—at least that's what science tells us. But why birth order matters goes deeper than just getting the best batch of genes from the parental pool. If siblings basically contain the same genetic makeup, how are firstborns different from their younger counterparts? The reasons why those first in line are graced with a higher IQ comes from a cocktail of environmental and biological factors that differ from family to family. How smart its members are depends on everything from early intellectual stimulation to limited parental resources.

While the eldest typically ends up earning higher wages and better education than the rest of the family, being the oldest sibling also comes with a few downsides. Older children are likely to be punished more strictly than their younger siblings. The oldest is also often more of a people-pleaser. These facts about eldest children are pretty surprising—unless of course you're the genius oldest child, then you probably already know all of this.


  • Limited Family Resources Intellectually Deprive Younger Siblings

    Being the only child in the house for some time before another sibling comes along gives the eldest an intellectual edge from a very early age. At least for a while, this child will have access to 100% of their parents' resources and attention, whereas a second child can never have the same benefit. Because resources within a family are spread thinner as more children are born, the older child will generally have access before and at a greater level than their siblings. Parents can offer higher level linguistics and usually more educational assistance that what is given to younger children when they don't have to divide their time.

  • Firstborn Children Are More Likely To Pursue Higher Education

    Having more brain stimulation and a higher level of intelligence allows the oldest child to pursue a greater number of opportunities. Their learning capabilities paired with their thirst for approval play a key role in the eldest's drive to seek higher education. Firstborn children are an entire 16% more likely to attend university than any other child in the family. It could also be the reason why eldest children are more likely to snag higher-paying wages.

  • Firstborns Show More Intelligence Starting From A Year Old

    As early as a year old, the eldest child typically scores higher on IQ tests than younger siblings. In a study tracking the mental growth of kids from the womb until the age of 14, scientists found that the first kid simply gets more attention and intellectual stimulation.

    Engaging in educational activities gives the eldest child an advantage in linguistics, cognitive recognition, and complex problem solving. The intelligence gap they express only grows with age. Gaining an intellectual advantage early in life accelerates their growth in contrast to younger siblings who experience less brain stimulation during development and often have a slower learning rate.

  • Firstborn Children Learn To Speak Like Adults

    The eldest sibling in the family spends more time communicating with adults than with children, which boosts their linguistic skills and their capacity for comprehension. Their younger siblings, however, will spend more time interacting with their elder sibling. While the elder sibling is knowledgeable about complex language, they're typically still at the reading and speaking level of a child. The laterborn is exposed to a less mature environment, and therefore does not gain the same linguistic skills that the older child does.

  • Firstborns Receive More Attention From Their Parents

    Firstborns get first dibs on seemingly everything in life, especially attention from their parents. This attention doesn't always come in the form of affection though. Parents are typically more involved in intellectually stimulating activities with their firstborn kids than with their other children.

    Kids that come later down the line usually experience the negative side effects of birth order from their parents. Although still emotionally invested, parents spend less time on brain-stimulating activities such as reading, crafts, and music. Parents also typically indulge in riskier habits after their first children, such as smoking during pregnancy.

  • Firstborn Children Are More Ambitious Than Their Younger Siblings

    The eldest child of the family has a drive for seeking out more ambitious opportunities in life. The often achievement-oriented eldest thrives in environments that provide an intellectual challenge and room to impress.

    It's only natural that given the leadership role from birth, firstborns tend to strive for academic and work-related greatness. Studies show that the firstborn child is more likely to hold a leadership role than any of the other child in the family.