Does social-ecological context influence individual thought complexity? While cognitive complexity has been a highly studied construct since the 1950s, little is known of the connection between cognitive complexity and social-ecological stress. Previous studies have found relationships between harsh distal environmental factors and preference for authoritarian leadership structures, but no work directly evaluates the degree that the surrounding features of the local environment influence individual thought complexity. Thus, the social and environmental mechanisms that contribute to individual thought complexity remain largely speculation. The present two studies fill in this gap by examining the relationship between social-ecological factors as measured at the cultural level (e.g., resource scarcity and diversity/inequality) and integrative complexity in political speeches as measured at the individual level (with the highly validated Natural Language Processing tool AutoIC). Study 1 used state-level markers of resource scarcity (e.g., poverty) and inequality (e.g., GINI Index) from US states to predict the integrative complexity of individual governor speeches for State of the State and Inaugural addresses over a 20-year period. Study 2 used similar nation-level markers of resource scarcity and inequality to predict the integrative complexity of individual political leader speeches for State of the Union-style speeches in eight nations over a 30-year period. Results from both studies revealed that state/national resource scarcity and income inequality produced individual leaders with lower integrative complexity. This complexity-reduction effect was larger and more robust for resource scarcity across US states, whereas it was larger and more robust for inequality across nations. Additional analyses on complexity subtypes further suggested that difficult ecological environments reduced individual thought complexity due to a stress reduction effect. Taken together, these results importantly reveal the connection between the social-ecological contexts within which humans live and the individual cognitions they produce.