This chapter reviews the extensive literature on bias in favor of in-groups at the expense of out-groups. We focus on five issues and identify areas for future research: (a) measurement and conceptual issues (especially in-group favoritism vs. out-group derogation, and explicit vs. implicit measures of bias); (b) modern theories of bias highlighting motivational explanations (social identity, optimal distinctiveness, uncertainty reduction, social dominance, terror management); (c) key moderators of bias, especially those that exacerbate bias (identification, group size, status and power, threat, positive-negative asymmetry, personality and individual differences); (d) reduction of bias (individual vs. intergroup approaches, especially models of social categorization); and (e) the link between intergroup bias and more corrosive forms of social hostility.

Review of the theoretical and empirical literature on homesickness showed that despite recent advances, scientific understanding of the impact on students of leaving home for college is still limited. Further empirical investigation using standardized measures, structural equation models and including additional mediating/moderating variables is needed. Two studies were thus conducted, one in the Netherlands, and one in the UK. Homesickness was investigated among recent-intake students, using a newly developed instrument, the Utrecht Homesickness Scale. Variables investigated in relationship to homesickness included depression, personality factors (self-liking, competence, self-esteem) and family situation (attachment to family). Homesickness was found to be a common though differentially prevalent phenomenon (approximately 50% in the Netherlands; 80% in the UK). Structural equation models showed that students missed family and friends and had difficulties adjusting to college life. These difficulties were associated with ruminations about home and loneliness, which themselves were associated with depression. There were differences in intensity (UK students were more homesick) and there were gender differences (UK females experienced more homesickness). Both the personality and family situation factors had an impact on homesickness. The results supported the conceptualization of homesickness as a 'mini-grief', to be viewed from theoretical perspectives in the field of loss and bereavement.

A field experiment provided the first test of the hypothesis that intergroup attitudes within a nation predict the group members' attitudes toward the break-up of the nation. Prior to a referendum on the devolution of power from Britain to Wales, Welsh (minority) and English (majority) participants indicated their attitudes towards each other and towards devolution. As expected, there were significant correlations between intergroup attitudes and attitudes towards devolution, and these relations were different for Welsh vs. English participants. English respondents who held more positive attitudes towards Welsh people were significantly more favourable toward devolution, whereas Welsh respondents who held more positive attitudes towards English people were significantly less favourable towards devolution. A subsequent laboratory experiment provided a conceptual replication of this result, using manipulations of majority vs. minority status and of intergroup attitudes towards potentially devolving groups in psychology. These findings demonstrate that intergroup attitudes are highly relevant to understanding attitudes regarding devolution.