Cognitive sociology has been split into cultural and interdisciplinary traditions that position themselves differently in relation to the cognitive sciences and make incompatible assumptions about cognition. This article provides an analysis and assessment of the cognitive and methodological assumptions of these two traditions from the perspective of the mechanistic theory of explanation. We argue that while the cultural tradition of cognitive sociology has provided important descriptions about how human cognition varies across cultural groups and historical periods, it has not opened up the black box of cognitive mechanisms that produce and sustain this variation. This means that its explanations for the described phenomena have remained weak. By contrast, the interdisciplinary tradition of cognitive sociology has sought to integrate cognitive scientific concepts and methods into explanatory research on how culture influences action and how culture is stored in memory. Although we grant that interdisciplinary cognitive sociologists have brought many fresh ideas, concepts and methods to cultural sociology from the cognitive sciences, they have not always clarified their assumptions about cognition and their models have sketched only a few specific cognitive mechanisms through which culture influences action, meaning that they have not yet provided a comprehensive explanatory understanding of the interactions between culture, cognition and action.