Abstract
Having a vision and being able to imagine socially and ecologically just alternatives can motivate people for societal transformation. However, which psychological processes drive this link between the mental accessibility of societal alternatives and collective action? We hypothesized that collective efficacy beliefs and politicized identification form two pathways mediating the effects of cognitive alternatives on high-cost activist behaviour. Two studies and a pooled analysis tested these hypotheses longitudinally. Data were collected in two field settings: a climate camp and an online conference on socio-ecological visions. In line with our assumptions, and across three of the four analysed timeframes, latent change score modelling showed that changes in cognitive alternatives predicted changes in collective efficacy beliefs and social movement identification, which in turn, predicted changes in collective action intentions. We found clear evidence for our hypotheses in the short term and mixed evidence in the long term. Additional analyses including participative efficacy showed no relevant effects. We concluded that the ability to envision social change may foster a sense of agency as members of social movements. These processes linking imagination to activism are less about individual efficacy than about realizing the collective possibilities for change and identifying with the groups enacting it.