Acculturation refers to the psychological, social, and cultural transformation that takes place through direct contact between two cultures, wherein one or both engage in adapting to dominant cultural influences without compromising their essential distinctiveness. It occurs when an individual acquires, adopts, or adjusts to a new cultural environment as a result of being placed into another culture or when another culture is brought into contact. This balancing process can result in a mixed society with prevailing and blended features or with splintered cultural changes, depending on the sociopolitical atmosphere. Individuals from other cultures work toward fitting into a more prevalent culture by selectively integrating aspects of the dominant culture, such as its cultural traits and social norms, while still holding onto their original cultural values and traditions. The impacts of acculturation are experienced differently at various levels by both the adoptees of the mainstream culture and the hosts of the source culture. Outcomes can include marginalization, respectful coexistence, destructive tensions, integration, and cultural evolution.

Levels and dynamics At a group level, acculturation often results in changes to culture, religious practices, health care, and other social institutions. There are also significant ramifications on the food, clothing, and language of those becoming introduced to the overarching culture.

At the individual level, the process of acculturation refers to the socialization process by which foreign-born individuals blend the values, customs, norms, cultural attitudes, and behaviors of the overarching host culture. This process has been linked to changes in daily behavior, as well as numerous changes in psychological and physical well-being. As enculturation is used to describe the process of first-culture learning, acculturation can be thought of as second-culture learning.

Under natural circumstances which are common in daily life encountered today, acculturation automatically takes a long time spanning several generations. Physical force can be seen in some instances of acculturation, which can cause it to occur more rapidly, but it is not a main component of the process. More commonly, the process occurs through constant pressure and consistent exposure to the more prevalent host culture.

Scholars in different disciplines have developed more than 60 theories of acculturation, though many lack academic rigour in their proposals. Active academic focus on the concept of acculturation began in 1918. As it has been approached from the fields of psychology, anthropology, and sociology at different times, numerous theories and definitions have emerged to describe elements of the acculturative process. Despite definitions and evidence that acculturation is a two-way process of change, theory and research have dealt mainly with the minorities' adaptations and changes such as immigrants, refugees, and indigenous people in response to their contact with the dominant majority. Contemporary research has primarily focused on the various strategies of acculturation within societies, the factors influencing the acculturation process and the individuals involved, and the development of interventions aimed at facilitating smoother transitions.

Historical approaches The history of Western civilization, and in particular the histories of Europe and the United States, are largely defined by patterns of acculturation.

One of the most notable forms of acculturation is imperialism, the most common progenitor of direct cultural change. Although these cultural changes may seem simple, the combined results are both robust and complex, impacting both groups and individuals from the original culture and the host culture. Acculturation with dominance has been researched by sociologists, anthropologists, and historians virtually only, mostly in a colonialism context, due to the dispersal of western European people all over the world over the last five centuries.Nutini, Hugo G. "Acculturation". In Davíd Carrasco (ed.). The Oxford Encyclopedia of Mesoamerican Cultures. : Oxford University Press, 2001

The first psychological theory of acculturation was proposed in W.I. Thomas and Florian Znaniecki's 1918 study, The Polish Peasant in Europe and America. From studying Polish immigrants in Chicago, they illustrated three forms of acculturation corresponding to three personality types: Bohemian (adopting the host culture and abandoning their culture of origin), Philistine (failing to adopt the host culture but preserving their culture of origin), and creative-type (able to adapt to the host culture while preserving their culture of origin). In 1936, Redfield, Linton, and Herskovits provided the first widely used definition of acculturation as:

Long before efforts toward racial and cultural integration in the United States arose, the common process was assimilation. In 1964, Milton Gordon's book Assimilation in American Life outlined seven stages of the assimilative process, setting the stage for literature on this topic. Later, Young Yun Kim authored a reiteration of Gordon's work, but argued cross-cultural adaptation as a multi-staged process. Kim's theory focused on the unitary nature of psychological and social processes and the reciprocal functional personal environment interdependence.Kim, Young Yun (2005). Adapting to a New Culture. In Gudykunst, W (Ed.), Theorizing about intercultural communication. Thousand Oaks, California: Sage Publications. Although this view was the earliest to fuse micro-psychological and macro-social factors into an integrated theory, it was clearly focused on assimilation rather than racial or ethnic integration. In Kim's approach, assimilation is unilinear and the sojourner must conform to the majority group culture in order to be "communicatively competent." According to Gudykunst and Kim (2003)Gudykunst, W. & Kim, Y. Y. Communicating with strangers: An approach to intercultural communication, 4th ed. New York: McGraw Hill. the "cross-cultural adaptation process involves a continuous interplay of deculturation and acculturation that brings about change in strangers in the direction of assimilation, the highest degree of adaptation theoretically conceivable." This view has been heavily criticized, since the biological science definition of adaptation refers to the random mutation of new forms of life, not the convergence of a monoculture (Kramer, 2003).

In opposition to Gudykunst and Kim's adaptive development, Eric M. Kramer developed his Cultural Fusion theory (2011,Kramer, E. M. (2011). Preface. In Croucher, S. M. & Cronn-Mills, D., Religious misperceptions: The case of Muslims and Christians in France and Britain . (pp. v-xxxi). Cresskill, NJ: Hampton Press. 2010, 2000a, 1997a,Kramer, E. M. (2010). Immigration. In R. L. Jackson, II (Ed.), Encyclopedia of identity . (pp. 384-389). Thousand Oaks: Sage.Kramer, E. M. (1997). Modern/Postmodern: Off the Beaten Path of Antimodernism. Westport, CT: Praeger. 2000a,Kramer, E. M. (2000). Cultural fusion and the defense of difference. In M. K. Asante & J. E. Min (Eds.), Socio-cultural Conflict between African and Korean Americans (pp. 182-223). New York: University Press of America.Kramer, E. M. (Contributing Editor). (2003). The Emerging Monoculture: Assimilation and the "Model Minority". Westport, CT: Praeger. 2011,Kramer, E. M. (2011). Preface. In Croucher, S. M. & Cronn-Mills, D., Religious Misperceptions: The case of Muslims and Christians in France and Britain (pp. vii-xxxii). Cresskill, NJ: Hampton Press. 2012Kramer, E. M. (in press). Dimensional accrual and dissociation: An introduction. I In J. Grace (Ed.), Comparative Cultures and Civilizations (Vol. 3). Cresskill, NJ: Hampton.) maintaining clear, conceptual distinctions between assimilation, adaptation, and integration. According to Kramer, assimilation involves conformity to a pre-existing form. Kramer's (2000a, 2000b, 2000c, 2003, 2009, 2011) theory of Cultural Fusion, which is based on systems theory and hermeneutics, argues that it is impossible for a person to unlearn themselves and that by definition, "growth" is not a zero-sum process that requires the disillusion of one form for another to come into being but rather a process of learning new languages and cultural repertoires (ways of thinking, cooking, playing, working, worshiping, and so forth). That is, in Kramer's view, one does not need to unlearn a language to learn another language, or unlearn who he or she is to learn new patterns of dancing, cooking, speaking, etc. Kramer disagrees with Gudykunst and Kim (2003) in saying that this commingling of language and culture generates cognitive complexity, or being able to switch between cultural repertoires. In short, Kramer says that learning is expansion, not unlearning.

Conceptual models

Theory of Dimensional Accrual and Dissociation

Although different acculturation models can be differentiated, the most complete models take into account change occurring in both groups as well as among the members of these interacting groups. To understand acculturation at the group level, one must first look at the nature of both cultures before coming into contact with one another. A useful approach is Eric Kramer's theory of Dimensional Accrual and Dissociation (DAD). Two fundamental premises in Kramer's DAD theory are the concepts of hermeneutics and semiotics, which infer that identity, meaning, communication, and learning all depend on differences or variance. According to this view, total assimilation would result in a monoculture void of personal identity, meaning, and communication. Kramer's DAD theory also utilizes concepts from several scholars, most notably Jean Gebser and Lewis Mumford, to synthesize explanations of widely observed cultural expressions and differences.

Kramer's theory identifies three communication styles (idolic, symbolic, or signalic) in order to explain cultural differences. In this theory, there is no single means of communication automatically better, and no last word on intercultural conflict presented. Kramer presents three connected theories instead: the theory Dimensional Accrual and Dissociation, the Cultural Fusion Theory and the Cultural Churning Theory.

For instance, according to Kramer's DAD theory, a statue of a god in an idolic community is god, and stealing it is a highly punishable offense. For example, many people in India believe that statues of the god Ganesh – to take such a statue/god from its temple is more than theft, it is blasphemy. Idolic reality involves strong emotional identification, where a holy relic does not simply symbolize the sacred, it is sacred. By contrast, a Christian crucifix follows a symbolic nature, where it represents a symbol of God. Lastly, the signalic modality is far less emotional and increasingly dissociated.

Kramer refers to changes in each culture due to acculturation as co-evolution. Kramer also addresses what he calls the qualities of out vectors which address the nature in which the former and new cultures make contact. Kramer uses the phrase "interaction potential" to refer to differences in individual or group acculturative processes. For instance, the process of acculturation varies significantly in the case of individuals who were immigrating to the host nation as refugees or immigrants. Furthermore, this process encompasses the importance of how hospitable the host society is to the newcomer, how welcoming the host is toward accommodating and acquainting the newcomer, and how their interaction affects the host and the newcomer.

Fourfold models