Multiple group membership and collective action: study 1&2

Datasets from two studies, conducted in Poland, on the relation between identity fusion, group identification, multiple group membership, perceived injustice, and collective action intention. The purpose of the present studies was to examine (a) whether multiple group membership (in the context of opinion-based groups) relates to collective action (CA) tendencies and (b) to what extent group efficacy belief, feeling of injustice, group identification, and identity fusion mediate the relation between multiple group membership and CA tendencies among Polish protesters against attempts by the government to restrict access to abortion. Two studies among Facebook opinion-based group users were conducted. In study 1, 181 users participated (108 women; Mage = 25.1, SD = 8.90), and in study 2, 262 users participated (146 women; Mage = 25.6, SD = 6.70). The results showed that multiple group membership is related to collective action tendencies, even when other important predictors of CA are accounted for (studies 1 and 2). Group efficacy belief partially mediates the effect of multiple group membership on CA tendency and has a positive effect on CA tendency (studies 1 and 2). Furthermore, group efficacy belief fully mediates the relationship between group identification and CA tendency (study 2). Perceived injustice fully mediates the relationship between identity fusion and CA (study 1).