Wives are usually younger than their husbands. Although this has been replicated across time and culture, there is no previous evidence of the likely evolutionary underpinnings of this age gap. Study Set 1 replicated the marriage age gap-and its moderators-in 6.4 million American marriages that led to U.S. births between 2016 and 2018. This effect also replicated in three million unmarried unions. Study 2 directly examined the life history tradeoff that connects the marriage age gap to selective fitness. When husbands are somewhat older than wives (but neither much older nor much younger), selective fitness is high, as operationalized by rates of short-term infant survival and neonatal breastfeeding. This pattern held independent of the robust effects of maternal age. Eight cross-cultural replications involving more than 225,000 mothers in low- to moderate-income nations examined lifetime selective fitness (total number of living children) rather than single birth outcomes. In all eight nations, analyses revealed both a husband-older age gap and a life history tradeoff in lifetime selective fitness. Life history tradeoffs account well for the husband-older age gap in marriage. (PsycInfo Database Record (c) 2021 APA, all rights reserved).

中文翻译：

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婚姻中的丈夫年龄差距与选择性健身有关。

妻子通常比丈夫年轻。尽管这已在不同时间和文化中复制，但之前没有证据表明这种年龄差距可能存在进化基础。研究集 1 在 2016 年至 2018 年间导致美国出生的 640 万次美国婚姻中复制了结婚年龄差距及其调节因素。 这种影响也在 300 万个未婚结合中复制。研究 2 直接检验了将结婚年龄差距与选择性健康联系起来的生活史权衡。当丈夫比妻子大一些（但既不大也不小）时，选择性适应度就很高，这体现在短期婴儿存活率和新生儿母乳喂养率上。这种模式独立于母亲年龄的强大影响。八次跨文化复制，涉及超过 225 个，中低收入国家的 000 名母亲检查了终生选择性健康（存活儿童总数）而不是单胎结果。在所有八个国家中，分析都揭示了丈夫年龄差距和一生选择性健康方面的生活史权衡。生活史权衡很好地解释了婚姻中丈夫年龄较大的差距。（PsycInfo 数据库记录 (c) 2021 APA，保留所有权利）。