The cultural trade-offs of migration: Innovation, assimilation, and the maintenance of adaptive institutions and norms

Migration is a major mechanism of cultural transmission, yet migration research commonly treats culture as secondary, while cultural-evolutionary accounts emphasize immigration's contribution to innovation without making the cultural foundations of successful receiving societies endogenous. This paper develops a more conditional framework. Migration enlarges the pool of ideas, skills and techniques available for recombination, but also moves potentially maladaptive norms, values and institutions between societies. Its effects therefore depend on what migrants bring, what and how quickly they adopt and how receiving populations respond. The paper distinguishes three ideal-typical settings: power-backed settler migration; gradientascending migration from less functional societies into more adaptive institutional orders; and diasporic-niche migration by groups carrying portable repertoires with comparative advantages. It then classifies cultural traits along two dimensions: additive versus substitutive, and modular versus integrated. Innovation gains should be concentrated among additive, modular traits that can be recombined without displacing existing practices. The greatest risks to adaptive institutions arise from substitutive, integrated traits, including generalized trust and commitments to common public goods, tolerance and acceptance of the rights of others, attitudes on religious authority, and shared narratives about constitutive issues. In these domains, assimilation may be functionally necessary but also the most difficult. A qualitative case study traces the rise of freedom to criticize and mock religion in Western Europe and its partial retreat through threats, violence and anticipatory self-censorship surrounding alleged blasphemy. It illustrates how a determined minority can alter a cooperative cultural equilibrium without becoming a demographic majority, and why effective institutions cannot simply be assumed to be fixed and stable when faced with imported illiberal norms. A subsequent quantitative analysis compares Turkish immigrants and their descendants to both the population in Turkey and the general population in Germany on attitudes regarding individual rights of women, homosexuals and the freedom of speech, religious fundamentalism, hostility towards religious outgroups, and conspiracy beliefs about outgroups. On all these dimensions, the first Turkish immigrant generation is very close to the population in Turkey and far removed from the German population average. The German-born second Turkish immigrant generation has moved somewhat in the direction of the German population's views but still is much closer to the population in Turkey. Assimilation thus proceeds least where it is needed most, namely regarding values that are key to maintaining a free, tolerant and cohesive society. These differences cannot be reduced to socioeconomic composition. Education is associated with more liberal views, but controlling for it explains only a limited part of the group contrasts. The paper thereby moves beyond both overly optimistic claims that unilaterally emphasize innovation gains and assume assimilation to be swift and frictionless. Instead, it specifies when migration can promote innovation and when it may weaken the adaptive institutions that make destination societies attractive in the first place.