This study tests the hypothesis that societal change from subsistence agriculture to a market economy with higher levels of formal schooling leads to an increase in individualistic values that guide human development. Values relating to adolescent development and the transition to adulthood were compared across three generations of women in 18 families in the Maya community of Zinacantán in southern Mexico. Grandmothers grew up in Zinacantán when it was a farming community; mothers grew up during the introduction of commerce in the late 1970s and 1980s; daughters are now experiencing adolescence with an opportunity to attend high school in their community. Comparisons were also conducted between 40 female and male adolescents in high school and a matched sample of 40 adolescents who discontinued school after elementary. Values were measured using eight ethnographically derived social dilemmas about adolescent relationships with parents and peers, work and family gender roles, and sexuality and partnering. One character in the dilemmas advocates for interdependent values; a second character advocates for independent values. High school adolescents were more likely to endorse characters articulating independent values than non–high school adolescents, mothers, and grandmothers. Involvement in a market economy was also associated with higher levels of independent value endorsement in the mother and grandmother generations. Results suggest that the introduction of commerce drove value changes between grandmother and mother generations, and now schooling drives change. Qualitative examples of participants’ responses also illustrate how families negotiate shifting values.