Findings from research on parent-child and adult mate relationships suggest that there are different paths of development in Japan and the United States. In Japan, the path is one of symbiotic harmony, as seen in the emphasis on union in infancy, others' expectations in childhood, the stability of relationships with parents and peers in adolescence, and assurance about the mate relationship in adulthood. In the United States, the path is one of generative tension, as seen in the tug between separation and reunion in infancy, the emphasis on personal preferences in childhood, the transfer of closeness from parents to peers in adolescence, and the emphasis on trust-a faith and hope in new relationships-in adulthood. The notion that there are different paths of development challenges Western investigators' presumption that certain processes-separation-individuation, use of the relational partner as a secure base for exploration, and conflict between partners-are central in all relationships. The notion of different paths also challenges the assumption of many cross-cultural investigators that relationships in the United States are less valued or weaker than those in Japan; this article highlights cultural differences in the meaning and dynamics, as opposed to the importance and strength, of relationships. The model suggests a need to investigate the processes underlying, and the adaptive consequences of, these two alternative paths.