Cultural globalization, which has led to increased intercultural contact, has emerged as a defining influence on contemporary societies worldwide. In the present study, we examined individual differences in endorsement of multicultural acquisition and ethnic protection, as well as their links with well-being indirectly through dimensions of personal identity development, in a sample of Danish emerging adults (N= 377;M[subscript age] = 22.68;SD = 2.25). Results indicate that a defensive reaction to cultural globalization, characterized by endorsement of ethnic protection, was directly and negatively associated with psychological well-being, whereas a proactive reaction characterized by multicultural acquisition was positively and indirectly linked to well-being through identification with identity commitments and through reflective identity exploration in depth. In terms of direct links between identity dimensions and well-being outcomes, identification with commitments was linked with satisfaction with life and with the hedonic dimension of psychological well-being, and reflexive exploration in depth was associated with the eudaimonic dimension of psychological well-being. These findings emphasize, within a Western cultural context, the ways in which an ethnic-protectionist approach to viewing diversity can be detrimental to well-being -- and that embracing diversity may help to facilitate well-being.