Although the previous chapter focused on the role of difference in collective identification, it still makes sense to say that the emphasis in collective identification falls upon similarity. Group identification, by definition, presupposes that members will see themselves as minimally similar. Categorisation is predicated upon the proposition that those who are categorised have a criterion of identification in common. Collectivity means having something in common, whether ‘real’ or imagined, trivial or important, strong or weak. Without some commonality there can be no collectivity.