International Conference on Environmental Psychology: "Theories of change and social innovation in transitions towards sustainability" A Coruña (Spain), August 30-31 and September 1, 2017. www.icep2017.org International Symposium organized by the IAAP (International Association of Applied Psychology) , Division of Environmental Psychology http://www.iaapsy.org/divisions/division4 , to promote the science and practice of applied psychology and to facilitate scientific exchange and communication on Environmental Psychology topics. The global dimension of contemporary societal problems such as climate change requires concerted action among different societal actors. Changing our lifestyles, societies and economies in a sustainable direction is possible only through broad consensus on the goals and pace of transformation Fast concerted action requires a keen understanding of the role of both individual and collective change agents and the mechanisms underlying their successes or failures in bringing about societal transformation. Both sustainable and social innovation initiatives, political actors and science itself are striving to understand the mechanisms for such transformation and harness their potential Research has long shown that people hold lay or implicit theories about themselves, others and the world at large, resulting in selective frameworks guiding perceptions and interpretations of events in the world, decision-making and action. Our implicit theories are motivated by a need to adapt to our complex physical and social environments and organize our actions in meaningful ways. They are also a result of our capacity for agency, by which we are "producers of experiences and shapers of events" Scientific theorizing has also aimed to uncover the trajectories sustainability and social innovation initiatives follow in their efforts to achieve social transformation, the motivations underlying individuals' involvement in environmental action, the patterns of interactions between individual and collective agency on the one hand and existing systemic factors constraining or facilitating their action on the other.