This paper presents a discussion about several theoretical models explaining collective mouvements. The theory of resources for movilization, the contradiction between the conception of an individual rationality and a collective one, based on a model of explanation stressing costs and benefits; the theory of the expected value that has been dominant in the psychology of motivation, and the theory of Reasoned Action, are examined from a critical perspective. The role of the collective action logic is considered in relation to collective and social motives, as well as the limitations of motivational models inspired in the expected value theory. Finally, a consideration about how social representations of radical Basques indicate how they can be helpful in explaining the relation between participation and psychosocial resources related to it, in such a way that collective action could be a strategic decition-making process based upon those representations.