Abstract: This paper explores the historical origins of collectivist cultural norms and their longterm economic consequences. In its first part, I test the hypothesis that collectivism emerged historically in pre-industrial agricultural economies in which group effort was crucial for subsistence. I find a positive and significant association between the traditional use of irrigation - a production mode that required extensive collaboration and coordination within groups of farmers - and collectivist norms today. Instrumenting traditional irrigation by the environmental suitability for irrigated agriculture lead to similar results that point at a causal interpretation of the findings. I find that the effects persist in migrants, and investigate factors that hinder the transmission of collectivism. The second part of the paper shows that by affecting culture, past irrigated agriculture continues to influence contemporaneous innovation at the national and individual level. While irrigated agriculture is associated with greater technological progress in pre-modern societies, this relationship is reversed in the long-run. In addition, by favoring attitudes towards obedience, past irrigation also predicts patterns of job specialization and selection into routine-intensive jobs of countries and individuals.