The DBO (Desires, Beliefs and Opportunities) theory of action proposed by analytical sociologists aims to provide an action-theoretical basis for building explanatory theories in sociology. Peter Hedström claims that the DBO theory is realistic because it does not make assumptions that are known to be false or seriously incompatible with the current scientific understanding about the nature of human action and cognition. This article nevertheless aims to show that the DBO theory is not only incomplete but also that its background assumptions are unrealistic, in the sense that they do not fit with the distributed nature of action-related cognition, which has recently become a growing topic of interest in cognitive sciences. The author also indicates that the neglect of the distributed and embodied aspects of cognition in the DBO theory leads to various biases in the process of constructing mechanism-based explanations in social sciences. Finally, an alternative approach to action theory is sketched on the basis of this critique.