Why is the empirical evidence for birth-order effects on human psychology so inconsistent? In contrast to the influential view that competitive dynamics among siblings permanently shape a person's personality, we find evidence that these effects are limited to the family environment. We tested this context-specific learning hypothesis in the domain of risk taking, using two large survey datasets from Germany (SOEP, n = 19,994) and the United States (NLSCYA, n = 29,627) to examine birth-order effects on risk-taking propensity across a wide age range. Specification-curve analyses of a sample of 49,621 observations showed that birth-order effects are prevalent in children aged 10–13 years, but that they decline with age and disappear by middle adulthood. The methodological approach shows the effect is robust. We thus replicate and extend previous work in which we showed no birth-order effects on adult risk taking. We conclude that family dynamics cause birth-order effects on risk taking but that these effects fade as siblings transition out of the home.

中文翻译：

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出生顺序对冒险行为的影响仅限于家庭环境

为什么出生顺序对人类心理影响的经验证据如此不一致？与兄弟姐妹之间的竞争动态永久塑造一个人的性格这一有影响力的观点相反，我们发现有证据表明这些影响仅限于家庭环境。我们使用来自德国（SOEP， n = 19,994）和美国（NLSCYA，n = 29,627）的两个大型调查数据集在风险承担领域测试了这种特定情境的学习假设，以检验出生顺序对风险承担的影响跨年龄范围的倾向。对 49,621 个观察样本的规格曲线分析表明，出生顺序效应在 10-13 岁儿童中普遍存在，但随着年龄的增长而下降，并在成年中期消失。方法论表明效果是稳健的。因此，我们复制并扩展了之前的工作，在这些工作中我们没有发现出生顺序对成人冒险行为的影响。我们得出的结论是，家庭动态会导致出生顺序对冒险行为的影响，但随着兄弟姐妹离开家庭，这些影响就会消失。