Across a wide range of pressing global challenges ranging from political polarisation, pandemics, prejudice and climate change, to trade wars and economic development, there is an underlying psychological feature that presents a barrier to progress: zero-sum thinking. Perceiving the relationship between individuals, groups, economies and social issues as zero-sum hinders the cooperation that has been a cornerstone to our species’ success. Yet surprisingly scant research has examined the psychological processes that underpin zero-sum thinking across domains and situations. This research investigates how a zero-sum mindset, that is, a generalised view of life as a zero-sum game, can shape perceptions, motivations and behaviours that diminish resources and increase hostility, thereby reinforcing a zero-sum game experience of the world. We present evidence from nine studies with 3,297 unique participants in the United Kingdom and in the United States using correlational, prospective and experimental research methods. Our results suggest that a zero-sum view of the world thwarts a society’s ability to flourish by undermining trust and cooperation, with serious consequences for the foundations upon which our wellbeing and our society is built.