Digital media are integrated into the lives of adolescents in almost every corner of the globe, yet the extent of integration, how media are used, and the effects of media in development are anything but universal. Much of what is known about adolescent digital media use and its consequences center on high-income economiesparticularly in the USA and Western Europe (e.g., Twenge et al., 2019;Vanden Abeele, 2016). Comparatively less is known about media use in lower-and middle-income economies, where digital media use has risen exponentiallyespecially among youthin a short period of time (Silver et al., 2019). Between 2000 and 2022, internet growth rates in Africa, Asia, Latin America/Caribbean, and the Middle East ranged from 2,300% to 13,000%, compared to 200-600% internet growth rates in Europe, North America, and Oceana/Australia during the same period of time (Internet Usage Statistics, 2022). Indeed, the increase in digital media use is now led by emerging and developing world regions (Poushter et al., 2018).The international perspective on digital media and adolescent development we provide in this chapter is important for a number of reasons. First, international perspectives help Western-based developmental psychologists such as ourselves appreciate human diversity and understand our own WEIRD (Western, Educated, Individualistic, Rich, Democratic;Henrich et al., 2010) perspectives on technology and human development. Second, cross-cultural research helps us to see how digital media such as mobile devices and social media platforms are cultural tools in the sociocultural tradition of Lev Vygotsky, rather than separate, disconnected, "virtual" places. Cultural tools are material and symbolic resources that accumulate through social processes across generations and that mediate human thinking and action (Cole & Scribner, 1978). Tools enable children to master psychological functions like memory, attention, and interpretation, which become implicated in a culture's definition of intelligence (Maynard et al., 2005). Although Vygotsky's theory is generally applied to cognitive development, the idea that digital media are cultural tools transforming human activity and psychological functioning can also be applied to social skills and identity development during the transition to adulthood (Manago et al., 2008).In conceptualizing digital media as cultural tools, we can examine the affordances or "opportunities for action" they offer, which are materially 162