Bias at Scale: Global Disparities in the Representativeness and Contextualization of Childhood Research.

Psychological science, including research on child cognition, behavior, and development, has traditionally relied on convenience samples drawn from a narrow range of sociocultural communities. Moving beyond the simplifying WEIRD/non-WEIRD dichotomy, this study estimates the global representativeness of children participating in developmental research across multiple metrics of human cultural experience. A systematic review of studies published between 2016 and 2020 in five leading journals reveals a disproportionate focus on children from communities situated at the extremes of all selected metrics. This bias is coupled with a selective disregard for cultural context in research originating from these overrepresented settings, reflecting a persistent double standard in how culture is treated across the field. Notably, studies involving children from underrepresented communities do not receive greater recognition (e.g., citations) unless they are embedded within larger, multinational research projects. We discuss the implications for representativeness, contextualization, and epistemic inclusion of these patterns, and we advocate for systemic change toward a genuinely global science of child development and psychological science more broadly.