“More households in developing countries own a mobile phone than have access to electricity or clean water” (World Bank Development Report, 2016). Despite the majority of the world’s populations and social media users living in the Global South, is our existing research on emergent technologies addressing questions that are accurately representing diverse populations and advancing scientific knowledge? Using a mixed-methodological and meta-scientific approach, I investigate this question and examine the nuanced effects of digital technologies in a hard-to-reach sample of rural women, and nationally representative adolescent samples across 13 countries in Sub-Saharan Africa, South Asia and South-East Asia. First, I develop a framework to reimagine diversity of the research samples routinely studied and measure both between-country and within-country diversity in social media research. Second, I present a mixed-methodological account to highlight the negativity bias (risks versus benefits) in research investigating the psychological impact of smartphones. I compliment these results by conducting a qualitative study into the impact of digital inclusion versus digital exclusion in 32 rural, hard-to-reach, low-income adolescents, and rural women in the context of South Asia which faces the world’s widest digital gender gap. Finally, I present findings from a nationally representative dataset of 11912 children and examine the prevalence and disclosure of online child sex abuse and exploitation in some of the worst affected countries with violence against children across regions of Africa and South-East Asia. Data from this thesis identifies culturally relevant barriers to overcome digital harms in Global South adolescents and provides critical meta-scientific insights to diversify psychological science.