This chapter introduces key themes of the "new psychology" of intergroup relations within systems, highlighting interconnection, intersectionality, temporal cycles, tipping points, and imagination. It challenges the limitations of ‘traditional’ psychology in addressing social change and emphasises the potential of these new approaches. The chapter begins by exploring systems thinking, recognizing that groups are internally divided and externally connected by intersecting identities, so changes within one element affect broader social structures. Intersectionality, critical theories and positioning theory are discussed to understand complex group interactions and power dynamics. The chapter also connects people and groups across time, emphasising the influence of historical context and the importance of future imagination in shaping present actions. It highlights the non-linear nature of social change, marked by tipping points. Finally, the chapter considers humans as part of larger biological and environmental systems, underscoring the interaction between social and physical environments, including the impact of climate change on group identities and norms.