From Basic Psychological Needs to Intergroup Solidarity: Integrating Self-Determination and Social Identity Perspectives on the Mobilization of Potential Allies

Abstract

This thesis investigates the motivations for solidarity-based actions, proposing and testing a need-based model rooted in Self-Determination Theory (SDT). Sampling lay audiences as potential allies to examine their proclivity towards solidarity with another group as a function of general basic needs, this thesis examines both potential allies' (self-focused) needs and their perceptions of the disadvantaged group's (other-focused) needs at individual and group levels. The actions studied are categorized as normative (e.g., donations, volunteering) and non-normative (e.g., blocking highways, spraying graffiti). In all studies, basic psychological needs (autonomy, competence, relatedness) were modelled as a composite construct due to high intercorrelations, while testing the effects of need satisfaction and frustration separately. Chapter 1 utilized two cross-sectional studies (N = 1232) involving contexts of incidental injustice, such as English citizens’ solidarity with Ukrainian refugees and students’ solidarity with striking university staff, to establish and refine the initial model. Key findings indicated that group need satisfaction (both self- and other-focused) was associated with intentions for normative solidarity (β =.09 to .24, p <.05), while group need frustration (both self- and other-focused) was linked to intentions for non-normative solidarity actions (β =.12 to .40, p<.05). Chapter 2 extended this framework by adopting a preregistered two-wave longitudinal design (N1= 589, N2= 273) to examine solidarity within a context of structural disadvantages (White British peoples’ solidarity with Black British people), aiming to capture the dynamic and evolving nature of need-based psychological processes over time. While the cross-sectional findings on need satisfaction were replicated, they largely disappeared over time. In contrast, need frustration remained a significant predictor. For White British participants, inconsistent with what SDT theorizing suggested, their ingroup need frustration at T1 positively predicted normative solidarity intentions at T2 (β=.21, p= .002) while their individual-level need satisfaction at T1negatively predicted non-normative solidarity intentions at T2 (β= -.09, p= .013). Though the effect of self-focused needs were consistent predictors of solidarity across models, the effect of outgroup need frustration on normative solidarity intentions was non-significant, though it trended in the expected direction (β=.17, p=.094). The results also hinted at potential feedback loops between self-focused needs and solidarity intentions suggesting that engagement in solidarity might lead to the internalization of the disadvantaged group’s cause and subsequently alleviate advantaged groups’ own need frustrations. Chapter 3 employed a preregistered between-subject experimental design (N=410) to test the causal impact of manipulating ingroup versus outgroup need frustration via mock news articles on solidarity intentions in the same context of racial inequality as Chapter 2. When participants found the mock news realistic, the expected effects of need frustration were successfully induced (β= -.91 & .66, for ingroup and outgroup respectively, p<.001), and in turn, outgroup frustration increased solidarity intentions while ingroup frustration reduced them (β=.34 and -.30 respectively, p< .01). Unexpectedly, these effects were reversed when participants judged the news as unrealistic, suggesting that low credibility may trigger reactance and defensiveness among advantaged group members. Taken together, this thesis highlights how basic psychological needs and the specific context (e.g., incidental versus structural inequality or the status of potential allies) determine the motivational pathways toward engagement in social change, providing crucial empirical basis for a broader discussion on the motivational landscape and the emergence and sustainability of solidarity.