Are there systematic trends around the world in levels of creativity, aggressiveness, life satisfaction, individualism, trust, and suicidality? This article suggests a new field, latitudinal psychology, that delineates differences in such culturally shared features along northern and southern rather than eastern and western locations. In addition to geographical, ecological, and other explanations, we offer three metric foundations of latitudinal variations: replicability (latitudinal gradient repeatability across hemispheres), reversibility (north-south gradient reversal near the equator), and gradient strength (degree of replicability and reversibility). We show that aggressiveness decreases whereas creativity, life satisfaction, and individualism increase as one moves closer to either the north or the south pole. We also discuss the replicability, reversibility, and gradient strength of (a) temperatures and rainfall as remote predictors, and (b) pathogen prevalence, national wealth, population density, and income inequality as more proximate predictors, of (c) latitudinal gradients in human functioning. Preliminary analyses suggest that cultural and psychological diversity often need to be partially understood in terms of latitudinal variations in integrated exposure to climate-induced demands and wealth-based resources. We conclude with broader implications, emphasizing the importance of north-south replications in samples that are not from Western, Educated, Industrialized, Rich, and Democratic (WEIRD) societies.