In the past decade, psychologists have made a welcome leap, expanding beyond a narrow focus on the North America, Europe and Australia in their research to include people from all over the world. One benefit has been greater insight on global distribution of cultural features—the society-level differences in psychological phenomena such as happiness, individualism and aggressiveness. Greater knowledge about the distribution of such features across the earth may help us better understand the many roots of cultural similarities and differences. Powerful cases in point are studies demonstrating that countries differ substantially in terms of mean happiness and the additional finding that this pattern is anything but random. In both the Northern and Southern hemispheres, happiness is higher in countries farther away from the equator (such as Denmark or New Zealand) than those closer to it (such as Vietnam or Cambodia).

Even more intriguing, we have uncovered the same pattern for individualism and creativity. Like happiness, these cultural features trend higher as one moves away from the equator. When we looked at aggressiveness, we found the opposite pattern: the closer you live to the equator, the more likely you are to exhibit aggressive behavior. To explain these robust links between latitude and culture—from happiness to aggressiveness and beyond—science needs a new field. Latitudinal psychology seeks to explain why societies differ so much and why location on the north-south axis of the earth is so critical.

Latitudinal psychology literally maps psychology and culture onto the world. It provides a new look at cultural differences and how they may have been developed. For example, perhaps lower happiness in locations closer the equator is primarily a function of less opportunities for economic development in the tropics and therefore fewer possibilities for personal growth. Such insights should be helpful not only to learn about the ecological roots of cultural differences but perhaps even to appreciate and respect them.

One explanation that may immediately come to mind is that climate shapes these cultural features. After all, latitude is strongly associated with climatological differences, such as annual temperature and rainfall. But climate does not work as a sole, or even primary, explanation, because it is associated with many other factors, including national wealth, the prevalence of viruses and other ecological risks, and natural hazards, any or all of which may play a role in a cultural feature such as happiness. What is needed, then, is a global perspective that focuses on key aspects of the natural or man-made environment that is shaped by climate and related factors. This latitudinal perspective seeks to understand cultural features such as happiness, creativity or individualism in terms of the global environment—the global ecology—which poses challenges to the individuals and groups that shape and reinforce these features. While the ecological perspective is growing in psychology, it is not extremely well documented in the literature. So a few illustrations should be helpful.

There has been some research showing that in countries farther away from the equator, people are more likely to have a clock culture, which emphasizes punctuality, as well as the overall importance of time and planning. The saying “Time is money” highlights a clock culture. In contrast, in nations closer to the equator, there is less emphasis on time and more on the appreciation of an event as it unfolds. Event cultures in these nations are perfectly captured in sayings such as “Give time to time” (“Darle tiempo al tiempo”) in Mexico or “Any time is Trinidad time” in Trinidad and Tobago, a country even closer to the equator than Mexico. An ecological interpretation is that time and planning are emphasized in cultures with large seasonal influences located at a greater distance from the equator, where one needs to plan for the next season (e.g., seasonal planning in agriculture and preparing for cold winters). Also, the potential for economic productivity may be greater in nations in those areas, and activities related to such productivity call for planning and a strong orientation on time.

There are more examples that show that latitudinal differences in location, even within the same country, are related to culture. For example, research in rural China revealed that people who live in southern regions where rice is produced tend to be more collectivistic and less individualistic than those who live in wheat-producing regions up north. Rice farmers increase economic benefit by working together, the researchers noted, whereas wheat farmers can (mostly) do the job on their own.

Turning back to the puzzle posed by the findings with which we began this article: How can we explain that happiness, creativity and individualism are higher, and that aggressiveness is lower, in countries farther way from the equator? Our analyses uncovered the importance of two ecological explanations: The first is wealth. Nations farther away from the equator are also wealthier on average, providing greater opportunities for education, along with autonomy and personal growth—features related to happiness, creativity and individualism. Conflict is less likely to be about survival than less urgent needs or concerns, which may help us understand why aggressiveness (often to outgroups) is weaker in wealthier countries. The second is natural threats, whether from pathogens (e.g., malaria), venomous animals (e.g., snakes) or natural hazards (e.g., flooding or drought). Such threats may not only undermine happiness and creativity but also bring about an orientation to those in a group to protect themselves from these risks, perhaps along with some aggressiveness to other groups.

Latitudinal psychology describes how cultural features are distributed over the world, with a focus on the north-south axis. Ecological perspectives are promising in explaining the origins of culture and why societies and nations can be so different from one another, in terms of happiness or aggression. Such knowledge may also help us better understand that not all populations are the same. This recognition is important because we increasingly face a new reality in which we are becoming more interconnected with other groups, cultures and societies. Indeed, psychology has to become broader and broader because the world is getting smaller and smaller.