Behavioral development in children shows large inter-individual variation, and is driven by the interplay between biological, psychological, and environmental processes. However, there is still little insight into how these processes interact. The YOUth cohort specifically focuses on two core characteristics of behavioral development: social competence and self-regulation. Social competence refers to the ability to engage in meaningful interactions with others, whereas self-regulation is the ability to control one’s emotions, behavior, and impulses, to balance between reactivity and control of the reaction, and to adjust to the prevailing environment. YOUth is an accelerated population-based longitudinal cohort study with repeated measurements, centering on two groups: YOUth Baby & Child and YOUth Child & Adolescent. YOUth Baby & Child aims to include 3,000 pregnant women, their partners and children, wheras YOUth Child & Adolescent aims to include 2,000 children aged between 8 and 10 years old and their parents. All participants will be followed for at least 6 years, and potentially longer.

In this paper we describe in detail the design of this study, the population included, the determinants, intermediate neurocognitive measures and outcomes included in the study. Furthermore, we describe in detail the procedures of inclusion, informed consent, and study participation.

儿童的行为发展表现出巨大的个体差异，并且是由生物、心理和环境过程之间的相互作用驱动的。然而，对于这些过程如何相互作用仍然知之甚少。青年群体特别关注行为发展的两个核心特征：社交能力和自我调节。社交能力是指与他人进行有意义的互动的能力，而自我调节是指控制自己的情绪、行为和冲动，在反应性和反应控制之间取得平衡以及适应当前环境的能力。 YOUth 是一项基于人群的加速纵向队列研究，通过重复测量，主要关注两组：YOUTH 婴儿和儿童以及 YOUth 儿童和青少年。 YOUth Baby & Child 的目标包括 3,000 名孕妇及其伴侣和儿童，而 YOUth Child & Adolescent 的目标包括 2,000 名 8 至 10 岁的儿童及其父母。所有参与者将被跟踪至少 6 年，甚至可能更长。

在本文中，我们详细描述了本研究的设计、研究对象、决定因素、中间神经认知测量和研究结果。此外，我们详细描述了纳入、知情同意和研究参与的程序。