Culture is a key determinant of children’s development both in its own right and for understanding the generalizability of developmental phenomena. Studying the role of culture in development requires information about participants’ demographic backgrounds. However, both reporting and treatment of demographic data are limited and inconsistent in child development research. A barrier to reporting demographic data in a consistent fashion is that no standardized tool currently exists to collect these data. Variation in cultural expectations, family structures, and life circumstances across communities make the creation of a unifying instrument challenging. Here, we present a framework to standardize demographic reporting for early child development (birth to 3 years of age), focusing on six sociodemographic construct categories biological information, gestational status, health status, community of descent, caregiving environment, and socioeconomic status. For each, we discuss potential measurement items and provide guidance for their use and adaptation to different contexts. These items are stored in a repository of context-adapted questionnaires that provide a consistent approach to obtaining and reporting demographic information so that these data can be archived and shared in a more standardized format. The public significance of this work is to facilitate diversification of participants within developmental psychology by providing a framework for capturing demographic diversity.