A Unified Approach to Group Processes and Motivation: Social Identity and Self-determination

Traditionally, the social identity approach (SIA; Tajfel & Turner, 1979; Turner et al., 1987) and self-determination theory (SDT; Deci & Ryan, 1985a; Deci & Ryan, 2002) frameworks have been studied independently of each other. A substantial amount of literature exists in support of the main tenets of both. Yet, an area of research has developed in which these two frameworks have been are brought together to form a unified approach. The current thesis aims to advance this area of research by examining the relationship between social identification, basic psychological needs, and regulatory types of motivation in the context of groups and different settings. Although previous research has adopted a unified approach, there has been a great deal of variation in how the various core components of each framework have been utilised. More research is required to consider how these relationships might change over time or how they relate to more direct measures of behaviour, such as performance outcomes. Lastly, much of the current research has focused on variable-centred methods (e.g., structural equation modelling), which cannot identify underlying heterogeneity where this might exist.

To address these limitations, this thesis begins by examining the underlying components of basic psychological needs from SDT (i.e., autonomy, competence, and relatedness) and SIA (i.e., centrality, satisfaction, and commitment) utilising both variable- and person-centred approaches (Chapter 3). The variable-centred approach used structural equation modelling. It offered a method for modelling the relationships between variables and using this information for predictions about outcome variables. The person-centred approach involved the use of latent profile analysis. It offered a method for understanding the underlying subgroups within the data instead of examining the results as though participants exist as a homogeneous group. The results of Study 1 (N = 281) showed that the relationship between social identification and perceived stress of employees was found to be mediated by need frustration. In Phase 2 (N = 281), the person-centred approach highlighted the heterogeneity in the population with six distinct subgroups (i.e., latent profiles) being identified. The findings highlighted the benefits of conducting the two approaches and initial evidence of the interplay between basic psychological needs and social identification.

In Chapter 4, Study 2 was an experimental approach (N = 250) that examined whether priming a meaningful social identity or competence support could facilitate improvements in performance on a choice reaction task. The results showed that performance improved with each trial under conditions of greater competence support (in alignment with SDT) and team identification (supporting the SIA). However, when these effects were combined, performance did not significantly improve. This unexpected result was hypothesised to be a consequence of excessive cognitive load and a heightened sense of pressure to perform well. Further findings reflected strategies that help groups to maintain or improve their social status (e.g., social competition). Yet, the lack of baseline measures means that some caution is required when considering these findings within the broader context of the unified approach.

Chapter 5 investigated the experiences of amateur footballers during a period of the football season. A longitudinal survey design was used to examine the role of initial team identification and satisfaction of basic psychological needs in predicting motivational profile membership at two points in time. Motivational profile membership was further examined in terms of burnout and physical health outcomes at time 1 and 2. In Study 3 (N = 338), latent profile analysis was used to identify the underlying subgroups, which were then used to confirm the profile identified for use in the longitudinal analysis. Overall, the study showed that motivational profiles remained largely stable across the football season. Adverse experiences of burnout and physical health were associated with membership of the least self-determined latent profile.

This thesis made several significant and novel contributions to advancing the unified approach literature. This thesis: 1) showed that the underlying motivational profiles were not captured by more traditional variable-centered analysis (i.e., structural equation modelling (SEM)) (Chapter 4); 2) through adopting a person-centered approach, identified distinct subgroups, showing the diversity of motivational and group experiences within a population (Chapters 4 and 6); 3) provided evidence of individuals within a seemingly homogeneous group (e.g., amateur footballers) exhibiting distinct profiles associated with motivation, basic psychological needs (BPN), and social identity (Chapters 4 and 6); 4) showed that motivational profiles have specific characteristics that shift over time, influenced by factors like team identification and the fulfillment of BPN (Chapter 6); 5) demonstrated that satisfaction of BPN and a strong sense of social identity contributed positively to motivational profiles, which in turn were linked to better performance and health outcomes (Chapters 4, 5, and 6); 6) showed that the combined priming effects of BPN and social identification were not associated with a boost in performance (Chapter 5); and 7) provided evidence towards better understanding the link between relatedness and social identity processes
(Chapters 4, 5, and 6).