The authors hypothesized that economically motivated voluntary settlement in the frontier fosters independent agency. While illuminating the historical origin of American individualism, this hypothesis can be most powerfully tested in a region that is embedded in a broader culture of interdependence and yet has undergone a recent history of such settlement. The authors therefore examined residents of Japan's northern island (Hokkaido). Hokkaido was extensively settled by ethnic Japanese beginning in the 1870s and for several decades thereafter. Many of the current residents of Hokkaido are the descendents of the original settlers from this period. As predicted, Japanese socialized and/or immersed in Hokkaido were nearly as likely as European Americans in North America to associate happiness with personal achievement (Study 1), to show a personal dissonance effect wherein self-justification is motivated by a threat to personal self-images (Study 2), and to commit a dispositional bias in causal attribution (Study 3). In contrast, these marker effects of independent agency were largely absent for non-Hokkaido residents in Japan. Implications for theories of cultural change and persistence are discussed.