Probing Birth-Order Effects on Narrow Traits Using Specification-Curve Analysis

The idea that birth-order position has a lasting impact on personality has been discussed for the past 100 years. Recent large-scale studies have indicated that birth-order effects on the Big Five personality traits are negligible. In the current study, we examined a variety of more narrow personality traits in a large representative sample ( n = 6,500–10,500 in between-family analyses; n = 900–1,200 in within-family analyses). We used...