Shortlisted for the 2024 Financial Times and Schroders Business Book of the Year Award. Acclaimed cultural psychologist and Columbia professor Michael Morris argues that our tribal instincts are humanity's secret weapon. Countries, churches, political parties, and companies are tribes, and tribal instincts explain our loyalties to them. Rather than deriding tribal impulses for their irrationality, we can recognize them as powerful levers that elevate performance, heal rifts, and set off shockwaves of cultural change.