Social Context, Life History, and the Biology of Human Development

生长和发展的过程对于理解人类生物多样性至关重要，而且由于正在进行的研究正在记录，因此必须在生物文化框架内进行调查，其中包括社会背景中的变化。 这项研究将有助于人类生物学的理解，阐明了发展机制的变化，在生活史参数的三个组成部分，什么是所谓的“成熟年龄“：青春期的年龄，初潮，和第一次生育。这些机制将在研究中儿童的社会环境背景下进行研究，填补我们对不同社会环境如何加速或延迟重要发展里程碑的理解中的关键空白。了解发育过程中的生物学机制对公共卫生有直接影响;早期发育是少女怀孕、乳腺癌和肥胖症的危险因素。 在美国，女孩在8岁时初潮的现象越来越普遍，这些早熟者可能面临各种不利健康后果的风险，这些后果不仅对个人，而且对整个社会都是昂贵的。先前的研究探讨了不利的社会环境的作用，如缺少父亲的家庭，对成熟年龄的影响，或儿童早期肥胖和体重指数对发育的影响。 这项研究的创新之处在于，在控制体型和生长的同时，同时测试社会背景对发育的影响，并在控制社会背景的同时测试体型和生长的影响。 研究设计具有前瞻性和纵向的优势，测量了1200多名男孩和女孩从婴儿到成年的生长和发育。这些受试者是正在进行的马里多贡人前瞻性队列研究的一部分。 通过关注这一研究人群，不仅可以获得丰富的关键数据，而且还可以大大提高在人类水平上理解基本生物学机制的潜力。调查不受混杂因素影响的人群的发育过程，如随时获得高质量的医疗保健，有助于发现进化的生物机制和生物投资平衡的关键方面（即，所谓的生命史权衡）。 更好地理解这些生活史权衡对于理解成熟年龄至关重要;因此，这项研究将增加人类生物学的科学知识，不仅是针对多贡人，而且是一般的智人。 通过这样做，该项目将提供对青春期的重要见解，这是一个人从童年过渡到成年的重要生命阶段。 一名美国研究生和一名马里大学生将接受主要研究者的指导，合作进行数据分析和手稿准备，以促进下一代科学家的教育。 美国本科生还将通过在研究现场进行当地基础设施开发的协作设计，为研究的积极社会影响做出贡献，同时提高他们在土木工程方面的知识和培训。 为了促进与其他研究人员的合作，并促进美国和马里的公共教育，将创建一个双语网站。研究结果将推动人类发展科学在人类学、心理学、生物学、人口学和公共卫生等广泛学科的发展。

The processes of growth and development are critical to understanding human biological diversity, and as ongoing research is documenting, this must be investigated in a biocultural framework that incorporates variation in social context. This study will contribute to the understanding of human biology by elucidating the developmental mechanisms that underlie variation in the life-history parameters of three components of what is termed "age at maturity:" age at puberty, menarche, and first birth. These mechanisms will be examined in the context of the social environment for the children in the study, filling critical gaps in our understanding of how different social contexts might accelerate or delay important developmental milestones. The understanding of the biological mechanisms involved in development has direct implications for public health; early development is a risk factor for teenage pregnancy, breast cancer, and obesity. In the United States, it is increasingly common for girls to reach menarche at eight years of age, and these early maturers may be at risk for a variety of adverse health outcomes that are costly--not only to individuals, but also to society at large. Prior research has explored the role of adverse social environments, such as families with absent fathers, on age at maturity, or the effects of early childhood obesity and body mass index on development. This study innovates by simultaneously testing for an effect of social context on development while controlling for body size and growth, and testing for an effect of body size and growth while controlling for social context. The research design has the advantage of being prospective and longitudinal, with measurement of the growth and development of over 1200 boys and girls from infancy to adulthood. These subjects are part of an ongoing, prospective cohort study of the Dogon people of Mali. By focusing on this study population, not only does a wealth of critical data become available, but the potential for understanding basic biological mechanisms at the level of the human species is greatly enhanced. Investigating developmental processes in a population not impacted by confounding factors, such as ready access to high-quality health care, facilitates detection of evolved biological mechanisms and key aspects of the balancing of biological investments (i.e., what are termed life-history trade-offs). A better understanding of these life history trade-offs is vital to understanding age at maturity; thus, the study will increase scientific knowledge of human biology, not just for the Dogon specifically, but for Homo sapiens in general. In so doing, the project will offer critical insights into adolescence, the important life stage in which an individual transitions from childhood to adulthood. A U.S. graduate student and a Malian university student will be mentored by the primary investigator, collaborating on data analysis and manuscript preparation so as to promote the education of the next generation of scientists. U.S. undergraduate students also will contribute to the positive societal impact of the study through the collaborative design of local infrastructure development at the research site, while advancing their knowledge and training in civil engineering. To foster collaboration with other researchers and to promote public education in the U.S. and Mali, a bilingual website will be created. The results should advance the science of human development in a wide array of academic disciplines, including anthropology, psychology, biology, demography, and public health.