Learning is one of the most important psychological processes for human growth and survival. Given it represents a person's ability to evolve and adapt across the course of a lifespan, it is no wonder that ability to learn is positively associated with health, wealth and happiness. It is therefore vital to understand this complex process, and particularly why learning seems easier for some than others. Learning is often assumed to be driven by personal aptitude, with discrepancies in learning outcomes attributed to individual differences in intelligence. However, data reveal that intellectual performance is highly stratified according to major identity-based categorizations such as gender, class, and ethnicity. Far from being representative of individual traits alone, academic outcomes therefore also appear to be socially mediated. This thesis sheds light on why social groups-and the social identities they afford-impact on learning outcomes, and in so doing demonstrates empirically that social identity cues are significant drivers of learning at implicit and explicit levels. To achieve this goal, the thesis is divided into two sections. The first section-Social Foundations of Learning-consists of basic research showing that a minimal sense of social inclusion impacts on implicit levels of information encoding. The second section-Social Facilitation of Learning-uses this knowledge to try to improve learning outcomes for students in real-world settings. The first chapter in Part 1 tackles the question of how to measure learning. Four experiments (total N = 658) design, test, and validate an online tool to measure implicit levels of encoding. A mini meta-analysis shows that the tool is as valid as traditional paper-and-pencil measures of encoding. Bringing together this cognitive measure with a social inclusion manipulation, the second chapter in Part 1 demonstrates that a minimal sense of social inclusion impacts on implicit encoding levels. Two experiments (total N = 336) provide empirical evidence that invoking a sense of social inclusion promotes cognitive encoding more than social exclusion. The second part of the thesis takes the research from the laboratory into the field, and specifically the classroom. The first chapter in Part 2 develops and validates an online tool to measure a person's sense of social connectedness, known as social identity mapping. Five studies (total N = 815) with diverse groups, including university students, new mothers, and retirees, demonstrate that online social identity Other publications during candidature Book chapters