Recently, biological aging has been quantified in DNA-methylation samples of older adults and applied as so-called “methylation profile scores” (MPSs) in separate target samples, including samples of children. This nascent research indicates that (1) biological aging can be quantified early in the life course, decades before the onset of aging-related disease, (2) is affected by common environmental predictors of childhood development, and (3) shows overlap with “developmental processes” (e.g., puberty). Because the MPSs were computed using algorithms developed in adults, these studies indicate a molecular link between childhood environments, development, and adult biological aging. Yet, if MPSs can be used to connect development and aging, previous research has only traveled one way, deriving MPSs developed in adults and applying them to samples of children. Researchers have not yet quantified epigenetic measures that reflect the pace of child development, and tested whether resulting MPSs are associated with physical and psychological aging. In this perspective I posit that combining measures of biological aging with new quantifications of child development has the power to address fundamental questions about life span: How are development and experience in childhood related to biological aging in adulthood? And what is aging?

最近，人们对老年人 DNA 甲基化样本中的生物衰老进行了量化，并将其作为所谓的“甲基化谱评分”(MPS) 应用到单独的目标样本（包括儿童样本）中。这项新兴研究表明，(1) 生物衰老可以在生命历程的早期进行量化，即在衰老相关疾病发生前几十年，(2) 受到儿童发育的常见环境预测因素的影响，(3) 显示与“发育过程”（例如青春期）。由于 MPS 是使用成人开发的算法计算的，因此这些研究表明童年环境、发育和成人生物衰老之间存在分子联系。然而，如果 MPS 可以用于连接发育和衰老，那么之前的研究只能采用一种方式，即推导出在成人中开发的 MPS 并将其应用于儿童样本。研究人员尚未量化反映儿童发育速度的表观遗传指标，并测试由此产生的 MPS 是否与身体和心理衰老有关。从这个角度来看，我认为将生物衰老的测量与儿童发展的新量化相结合，有能力解决有关寿命的基本问题：儿童时期的发展和经历与成年后的生物衰老有何关系？什么是衰老？