This research project will investigate multiple perspectives (migrant, host and intergenerational) on attitudes about integration, feelings of belongingness, group affiliation, and psychological and sociocultural adaptation of migrants. The proposed research project offers a new theoretical framework in which the bidirectional nature of the acculturation process is addressed. Acculturation theory and uncertainty-identity theory are integrated in order to investigate the possible consequences of uncertainty about oneself and belongingness. The main purpose is to understand (1) when and where conflicts and social tensions between host members and migrants as well as between generations arise, (2) why mal-adaptation of some proportions of migrants occur (e.g. identification with sub-groups to reduce uncertainty and oppose the host society), and (3) what intervening variables impact on positive outcomes (social cohesion, harmony). In three comprehensive studies, these key questions will be addressed. An advanced mixed-method approach will be employed to acknowledge different levels of analyses, namely the individual, regional and societal level. The proposed research will substantially contribute to the resolution of intercultural conflicts and the mechanism behind hostile attitudes. Moreover, it will be possible to explain the conflicts between hosts and migrants and offer ways of conflict resolution to build a more harmonious future. The findings will be very important and useful to equip host members and migrants as well as policy makers with the tools to work towards more positive outcomes and social cohesion.