This textbook offers a dynamic introduction to social psychology. It draws on material from Fundamentals of Social Psychology (Hayes), but is thoroughly revised and updated, placing applied research at the heart of the narrative and demonstrating its relevance to the challenges of contemporary society. It shows how social psychology moves beyond theory to explain and influence real-world behaviour, addressing issues that shape our everyday lives. Key themes include:How our thoughts, feelings, and behaviours are shaped by social interactions—from close relationships to digital communities. How social psychological principles inform real-world solutions in areas, such as health, education, organisational life, and social justice. How pressing social issues—moral decision-making, trauma, inequality, and adverse childhood experiences—can be understood and addressed through a social psychological lens. How social identity, relationships, and group dynamics shape development across the lifespan. The book introduces a brand-new chapter on social development and integrates applications of social psychology throughout every chapter, ensuring students see the direct link between research and practice. Designed as a core text for undergraduate and postgraduate courses, the book combines essential theory with research-in-action examples, boxed discussion points, and case studies drawn from current social challenges such as climate change, misinformation, and diversity in the workplace, aimed to encourage critical thinking and practical engagement.