In an age of migration, anticipating, directing, or stemming migration flows is a leading dilemma for policy makers confronting a broad range of concerns. A critical research finding is that migration flows can develop a self-sustaining momentum that is difficult to redirect. This phenomenon, predicted by cumulative causation theory, hypothesizes that migration flows gain momentum and eventually become self-sustaining due to the accumulation of migration experience in the form of migrant social capital. Migration studies evaluating the theory are substantial, especially for the Mexican-U.S. case, but also for other sites, powerfully demonstrating how macro social structures influence behavior and vice versa. However, recent research also shows that rather than uniformity in the macro-micro migration dynamic, instead there is still substantial heterogeneity in migration patterns at both the community and individual level. We propose that this heterogeneity in patterning can be explained by further theorizing the mechanisms that underlie cumulative causation. Specifically, we propose that migrant social capital evolves differently depending the historical continuity of migration flows to and from a particular destination and the social proximity of migrants to potential migrants in origin communities. We examine longitudinal data from Thailand to test this theoretical modification by estimating migration models to substantively different destinations, observing migration experiences at multiple levels of social proximity (individual, household, and community). Our models also include a gender account of these patterns, since gender is a fundamental social organizing mechanism. We find significant cumulative differences in migration patterns that can be explained by historical continuities to destinations and social proximity within origin communities. In addition, men’s and women’s accumulated migration experiences, differential social proximity, and differential access to migrant social capital demonstrate that heterogeneity in migration flows is also driven by gender.