Early Development in cross-country perspective: A systematic review of a quarter century of developmental research

The first years of life are characterized by rapid developmental changes across multiple domains, including neurobiological maturation, motor skills, socio-emotional characteristics, and cognitive abilities. These developmental processes are, in part, influenced by external factors such as culture and country. For this reason, the predominant contemporary reliance on so-called WEIRD populations poses a significant limitation to the generalizability of developmental theories. For the Special Issue, this review aims to present a cross-country perspective on early development by analyzing literature from the first 25 years of the 21st century published in Infant Behavior and Development. We screened 1768 documents and identified 58 studies that included data from multiple countries. The majority of these studies were authored by researchers from the United States, the United Kingdom, Germany, and the Netherlands. In this review, we categorized and discussed the studies into five recurring research domains, which encompass developmental processes: temperament, socio-emotional development, communication and language development, cognitive development, and motor development. The current review documents the growing interest in cross-country research on early development, yet also reveals notable gaps, particularly in studies of cognitive and motor development as well as neurodevelopmental processes. Most studies have focused on the influence of parenting and socialization practices on early development, mainly using cross-sectional data from high-income countries. However, expanding research to encompass a broader range of cultural contexts and developmental domains is essential to advancing the science of infancy. By fostering greater diversity in cultural perspectives, future studies can provide a more comprehensive understanding of how different environments shape early development. This development, in turn, can inform more effective, culturally responsive early childhood care and education practices worldwide.