Starting from a social assimilationist perspective, up to a mutual accommodation of cultures (e.g., integration), the concept and the theory of acculturation passed through several refinements during the last century (Gordon, 1964; Sam & Berry, 2006). A substantial body of literature suggested that integration orientation of individuals (e.g., biculturalism) together with a multiculturalist society is the best practice for minorities regarding health-related, psychological, and socio-cultural adjustment in a globalised world (Berry, 2006; Benet-Martínez & Harritos, 2005; Kaya, 2019; Kymlicka, 1995; Gaertner et al., 2000; González & Brown, 2006; Nespitt-Larking, 2014). However, Turkish postmigrants’ acculturation orientation constitute an exception for the premise of acculturation theory (Sam & Berry, 2006), although, in the early 2000’s, significant empirical evidence challenged the assumption about their ‘peculiarity’ (Diehl & Schnell, 2006; Kaya & Kentel, 2004). Eventually, a ‘decline of dual identity’ occurred during the last decade, since many studies repeatedly failed to meet the optimistic expectation of biculturalism among Turkish postmigrants (Baysu, Phalet & Brown, 2011; Felischmann, Phalet & Swyngedouw, 2013; Leszczensky, 2013; Sauer, 2018; Simon, Reichert & Grabow, 2013).

This dissertation aimed to understand the underlying social-psychological mechanisms of the decline of dual identity among Turkish postmigrants. Relying on the assumptions of rejection-(dis)identification models (Branscombe et al., 1999a; Jasinskaja-Lahti et al., 2009), we argue that the subjective aspect of rejection rather than objective experience of it, is under jeopardy among Turkish postmigrants that can be associated with extraterritorial outreach attempts of Turkey (Adamson, 2019; Glasius, 2018; Hatay & Tziarras, 2019b). To this end, we realised a three-year mixed methodological research (1) to contextualise rejection concept via a qualitative study (n = 26), (2) to associate demonstrated rejection components with the change in the ethnonational identification of Turkish postmigrants via a repeated cross-sectional survey (n = 1093) and (3) to re-conceptualise the well-known perceived discrimination variable in the light of previous findings via an experimental vignette study (n = 217).

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In the first study, we employed the stigma-induced identity threat model (Major & O'Brien, 2005) and found that Turkish postmigrants are physically or vicariously exposed to maltreatment and appraise the danger through personal and social resources and finally attribute the harmful incidents to particular agents or sources in order to overcome the adverse effects rejection. This study shows that the fear and concerns of rejection is more widespread than the actual encounter to social exclusion practices (Kloek, Peter and Wagner, 2015). Besides, Turkish postmigrants internalise the stigma of living in a parallel society (Hiscott, 2005) and attribute the rejection to their in-group apart from blaming Germans for rejection (Major, Quinton & McCoy, 2002). In the second study, we associated these components of rejection to the change of the ethnonational identification of Turkish postmigrants between 2008 and 2014 correspond to the shift in diaspora governance of Turkey (Adar, 2019; Arkilic, 2021; Hatay & Tziarras, 2019b). As expected, we found that ethnonational identification of Turkish postmigrants is more sensitive to the subjective components of rejection (e.g., appraisal of threat & causal attribution) rather than the objective rejection experiences. Finally, in the third study, we reconceptualised the discrimination (i.e., Justifiable, Perceived, Structural and Apprehensive) based on a combination of the appraisal of threat and causal attribution, and examined their main as well as interaction effects on the dual identification, political participation and resilience to violent extremism. We found that while a generalised threat (e.g., towards non-Germans) promote national identification, a specific threat (e.g., towards Turks) undermine the same and increase the ethnic identification. Besides, both appraisal of threat and causal attribution have the main effect on political participation, while their interaction only affects resilience to violent extremism.

Our careful investigation clarifies that instead of a decline of dual identity, a consolidation of ethnic identity occurs among Turkish postmigrants (Klein, Spear & Reicher, 2007). Accordingly, their insecure position both within the in-group in the face of extraterritorial outreach policies of Turkey (Adamson, 2019; Glasius, 2018) and the inter groups system in Germany in the face of increased new social exclusion waves (Kaya, 2019;

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Ramm, 2010), drive them toward their ethnic identity and detaches them from the national identity. However, our contextualised approach shows that framing the rejection via the loci of appraisal of threat and causal attribution might reverse the current trend of consolidation of Turkish identity in Germany. After the interpretation of diverse findings revealed from different methodologies, we draw a conclusion and discussed the possible policy as well as the scientific recommendations in the last section of the dissertation.