After World War II, Ukraine followed the psychological paradigm described by Arnold van Gennep in his book Rites of Passage. In this model, unifying peoples undergo a three-stage transformation. In the first stage of the process, a community senses what Gennep calls separation, in which it realizes that it is discontented with its traditional identity, but has not yet envisioned a clear alternative. In this stage, a group identifies itself by comparing itself with an other and noting differences. The first stage is followed by a transitional phase which Gennep refers to as liminality. In this phase, the group adopts a new identity, but has not shed its old identity entirely. Thus, the group in question may identify itself as a part of both its traditional identity and its new identity, or as a distinct subset of the traditional group. The final stage of aggregation occurs when the group has embraced a new identity, and by fully incorporating values and symbols particular to the group, completely discards its previous identity.