Brewer’s (1991) Optimal Distinctiveness Theory (ODT) suggests a two-dimensional model of inclusion (See Figure 1). She argues that for an individual to identify with a group, the individual does not only need to assimilate with the group members, but simultaneously satisfy differentiation needs. In this set of six studies, we test this assumption by comparing how the four cells of ODT predict identification with superordinate and in-group (i.e., subgroup, subordinate) identities and well-being. These mediations have been suggested by the Rejection-Identification Model (RIM; Branscombe, Schmitt, & Harvey, 1999), the Rejection-Disidentification Model (Jasinskaja-Lahti, Liebkind, & Solheim, 2009), and the Inclusion-Identification Model (IIM; Adams et al., in prep.). Note that we do not test these mediations in the six students pre-registered here. We only compare how the conditions affect identities and well-being, respectively. Mediation will be assessed in follow-up projects. More detail will be given in the PDF attached.