Current work on acculturation deals with several issues. First, the process is highly variable and has a number of possible outcomes (Berry 1980) depending on whether we focus on dominant (numerical, powerful) groups or non-dominant ones. One possibility is that the groups and individuals will merge to form a new culture that combines elements of both cultures (usually by the non-dominant group changing to become more like the dominant culture): this possibility has been termed assimilation. A second possibility is that the non-dominant group seeks to maintain its culture and avoids further contact with dominant group (termed separation). A third way (integration) occurs when both groups maintain their own cultures, adapting them so that their continuing contacts enable them to live together in a culturally plural society. The fourth possibility (marginalization) occurs when individuals and groups no longer value their own culture and do not seek to participate in the larger society. For many years, it was assumed that assimilation was the only and inevitable way for acculturation to take place; however, the continued existence of many cultural communities within diverse societies demonstrates that the other three ways are also possible. Integration is often the preferred way of acculturating (Berry 2002).
A second issue is whether change following contact will be only in the non-dominant group or will also be evident in the dominant group. Acculturative change is clearly underway in both groups: massive changes have occurred in immigrant-receiving societies, as well as among immigrant groups themselves. Increasingly, acculturation is recognized as a process of mutual accommodation, in which both (all) groups in contact change in the various ways outlined above.
A third issue is whether the process is a short-term one that is over and done with in few years. Historical and current evidence shows that changes continue over generations, starting with those first in contact, and continuing for their children and later generations. Cultural groups often do maintain themselves by way of the process of enculturation, and then continue to adapt to their ongoing intercultural contact, by way of acculturation.
Fourth is the distinction between process and outcome. Acculturation (the process) clearly takes place over time and has a complex course as groups and individuals try out the various ways of acculturating. However, at any one time, groups and individuals can be understood as acculturating in a particular way, with certain consequences. A distinction has been made between two forms of adaptation (Ward 1996): psychological and socio-cultural. The former refers to internal personal qualities (e.g., self-esteem, good mental health, a clear identity); the latter refers to relationships between the individual and the new sociocultural context (e.g., competence in living interculturally, in daily interactions in school and work). Successful acculturation requires both forms of adaptation evidenced by positive psychological and sociocultural adaptation. Integration is not only the most preferred way, but it is also the most successful (Berry 1997).