The European Union (EU) has suffered from fall-out recently. Clear cases in point were the anti-EU outcomes of the referenda in France and the Netherlands, as well as the messy process in response to the Euro crisis. More broadly, recent elections in many European countries have resulted in winning parties that advertise an explicit anti-EU sentiment, often linked to an equally explicit anti-immigrant stance. Apparently, in the eyes of many, the EU is not delivering - quite to the contrary. In this essay, insights from a variety of social sciences will be reviewed that may shed light on this issue, with a focus on the role of a multidimensional conception of diversity.