This article sheds light on the important differences in self-declared happiness across countries of equivalent affluence. It hinges on the different happiness statements of natives and immigrants in a set of European countries to disentangle the influence of objective circumstances versus psychological and cultural factors. The latter turns out to be of non-negligible importance in explaining international heterogeneity in happiness. In some countries, such as France, they are responsible for 80% of the country's unobserved idiosyncratic source of (un-)happiness.