The ‘double identity’ of Taiwanese as both Chinese and Taiwanese identity was measured among both general and student samples using categorical and continuous measures. As predicted, Mingnan (native province) Taiwanese were higher in Taiwanese identity whereas outside-province Taiwanese were higher in Chinese identity. Both groups shared similar representations of the history of Taiwan, but evaluations of leaders followed patterns of in-group favoritism. These representations of history were used to predict and find zero correlations between Chinese and Taiwanese identity. Taiwanese and Chinese identities were mutually compatible in cultural domains, and mediated the effect of demographic group. However, in issues concerning politicized allocation decisions (and language), Taiwanese and Chinese identity worked in opposite directions, and demographic group (and a critical evaluation of an historical leader) were significant even after controlling for identity. Implications for social identity theory, realistic group conflict theory, and the cross-straits relationship are discussed.