Owing to their heterogeneity, the various intermediate socioeconomic groups are defined by default as “neither really poor, nor really wealthy.” The vast literature devoted to the study of the middle class(es) shows that, in Africa, there is no systematic or automatic effect to be expected from this category as such. It is a crucial research subject nonetheless, because it not only reveals new social dynamics that impact the economy and politics, but it also permanently transforms our way of conceptualizing development and aid in the continent.