This study builds on studies on integration and message effectiveness to test whether narrative versus statistical evidence is more effective in fostering openness to Western European norms amid diverse subgroups of Muslim immigrants. It draws on an experiment in which Muslim immigrants residing in the Netherlands (N = 454) saw narrative or statistical messages about gender equality, sexual minority rights, and secularism in public life. It is found that the Dutch-born were more receptive to a narrative, while statistical messages produced greater openness to the tested norms amid those born in Muslim countries. These findings are interpreted in light of diverse cultural orientations. The inquiry proposes a first step toward a framework for grasping evidence effectiveness in multiethnic societies.