In 1874 Francis Galton reported that firstborn children were overrepresented as high achievers in various scientific fields. There were flaws in Galton's methodology, for instance, he did not count female children in his results. Male subjects were counted as a first born even if they were the tenth child, but the nine older siblings were female (Esping, 2003). However, Galton’s conclusion that birth order correlates with intelligence and academic attainment remains popular. Even in the last decade, other researchers, in both Europe and North America, have confirmed and reasserted Galton’s conclusion.
What studies have demonstrated that birth order influences intelligence and/or achievement?
Research by Christensen and Bjerkedal concluded that birth order has a small impact on educational attainment (Christensen & Bjerkedal, 2010). That conclusion has also been reported by other related studies. Analysis of the National Longitudinal Survey of Youth (NLSY) and the Wisconsin Longitudinal Study (WLS) show that birth order has an effect on educational attainment and intelligence (Retherford & Sewell, 1991 and Rodgers, Cleveland, van den Oord & Rowe, 2000). Also, earlier research on Norwegian male military conscripts also demonstrated that birth order impacts on intelligence (Bjerkedal et al., 2007). The confluence model theorizes that first born children are raised in an adult oriented, highly intellectual environment. Also, when first born children interact with their younger they adopt the role of teacher. This is known as the tutor effect (Zajonc& Sullaway ,2007).
Are studies that support birth order effect on intelligence and/educational attainment flawed?
Wichman, Rodgers and MacCallum suggest a critical flaw in previous research that supports that birth order has an effect on intelligence and/or educational attainment They suggest that in larger families the first born is...