Research Doctorate - Doctor of Philosophy (PhD) / The present work is a project in social psychology that looks at four different types of ingroup identification and investigates their possible variations as a function of defining personal characteristics and group-related phenomena. Five studies provide evidence for the validity of a qualitative distinction between centrality, social, communal, and interdependent identification and examine the way in which culture, gender, group status, relationship attachment style, and group type predicted each type of identification with groups. The research employs a multi-sample approach and combines correlational, experimental, and quasi-experimental designs. Research data was collected using purpose-built questionnaires that included a newly constructed Centrality, Social, Communal and Interdependent Identification Scale (CSCIIS) together with previously validated measures. Participants from Western and non-Western cultural backgrounds showed dispositional differences in their preferred type of identification, and differed in the extent to which their identification was focused on the group as a whole or on the individual group members. The studies integrate social identity theory, self-construal, and behavioural interdependence ideas, suggesting that there are some types of ingroup identification that are primarily based on interpersonal processes and relationships between group members. The leading themes are those of the conceptual complexity in assessing individuals’ identification with various social groups and the possibilities for deepening our understanding of the phenomenon by considering the key aspects that separate one type of ingroup identification from another. The results help bring clarity to a confusing literature dealing with ingroup identification and illustrate the value of a different level approach in the area.