Through primatology, I realized it was possible to examine sociality from a perspective outside of the human species. I joined Kyoto University's Laboratory of Physical Anthropology under the supervision of Imanishi Kinji and Itani Junichiro. I decided to pursue field-based discovery research on Japanese macaques and gorillas aligned with my mentor's frameworks. First, I traversed Japan, investigating macaque ecology, sociality, and morphologic variation. Next, Iinvestigated the socio-ecology of gorillas in Africa. I focused on Grauer's gorillas in Kahuzi-Biega National Park (Zaire), and mountain gorillas in Volcanoes National Park (Rwanda). These populations exhibited differences in the prevalence of multi-male groups, female migration patterns, and male group formations. Under the supervision of Dian Fossey in Rwanda, I studied male and group life histories. Following Fossey's tragic death and The movement of Karisoke Research Centre outside the park. I resolved to collaborate with local researchers and engage in community conservation activities. In Kahuzi, I studied the sympatric coexistence of gorillas and chimpanzees in higher and lower regions. They share habitats and diets but adopt different foraging strategies, particularly during periods of fruit scarcity. Early humans adopted a strategy of "turning weaknesses into strengths."This approach enabled us to colonize diverse environments inaccessible to other primates. Modern society has shifted toward a strategy of "amplifying strengths" through technology, leading to significant degradation of the environment. Field studies of nonhuman primates can shed light on the nature and origins of human societies. Continuation of field research is crucial for envisioning and shaping a prosperous future for humanity.