Billions of dollars are spent each year on development projects. Little is known about whether these resources change how the rural poor associate with available social categories. Is it possible that development projects change how individuals relate to concepts of 'ethnicity', 'low economic status' or any other culturally relevant form of social categorization? I explore this question with original data collected in the Democratic Republic of Congo. By exploiting exogenous variation in the presence of NGO activity across Congolese villages, I off er causal evidence that, paradoxically, development resources make individuals associate more strongly with their 'low economic status' social category even after the conclusion of the NGO program. To explain this result, I argue that Congolese signal to be poor in order to maximize the probability of obtaining access to development resources. Through repetition, this initially one-off strategic choice is internalized over time. This proposition is corroborated by evidence from a survey experiment among 1,929 Congolese respondents in the same villages. The study thus provides original evidence on the unintended, negative effects of development aid.