Societal polarization ranks among the most pressing global challenges, posing serious risks to social harmony, democratic stability, and collective well-being. This chapter draws on psychology and neuroscience to examine how ordinary differences can escalate into entrenched intergroup conflict. We review key psychological and neural mechanisms underlying intergroup conflict, including social categorization, stereotyping, personality traits, power, and echo-chambers. We then synthesize evidence-based interventions, from informational and contact-based approaches to emotion- and identity-focused strategies, that have been shown to reduce intergroup tensions and strengthen social cohesion. Together, these insights offer a roadmap for fostering more cooperative and socially harmonious societies.

This chapter examines political disagreement as a serious everyday problem, exploring why we struggle to engage with those who think differently about politics. Taking an identity-centered psychological approach, the chapter examines how political positions become tied to our sense of self, transforming policy disagreements into perceived threats. Drawing on research on social identity, motivated reasoning, and meta-perceptions, I explore how these processes create vicious cycles of avoidance in ordinary conversations – at family dinners, in workplaces, and across social media. The chapter then turns to evidence-based interventions, arguing that the solution lies not in eliminating disagreement but in building skills for productive dialogue, from conversational receptiveness to epistemic humility, alongside educational and institutional approaches that can cultivate democratic curiosity.

Football-related disorder remains a visible form of collective violence, generating substantial policing costs and persistent tensions around rights, legitimacy, and public order. Despite declines in organized “hooliganism,” football continues to be governed through highly resourced public order policing grounded in static assumptions about fan groups. We argue such approaches misdiagnose the problem. Drawing on Social Identity Theory and the Elaborated Social Identity Model, football disorder is conceptualized as an interactional and relational process shaped by legitimacy, identity, and institutional practice. Methodologically, the chapter advances an outward-facing, epistemologically pluralistic psychology integrating ethnography, interpretive analysis, and Participatory Action Research. Empirically, it compares developments in football policing in England and Wales with contemporary approaches in Switzerland. The UK case illustrates how dialogue-led, research-informed practice can foster legitimacy, self-regulation, and de-escalation, while the Swiss case shows how preemptive, legalistic controls undermine legitimacy, amplify oppositional identities, and escalate conflict.

Affective polarization is commonly defined and measured by combining positive attitudes toward one’s own political party and negative attitudes toward one or more opposing parties. It has aroused considerable public and academic attention because of its link to societal hostility, uncivil online discourse, declining cross-partisan interactions, political intransigence, and a hardening of party lines – all contributing to democratic backsliding. To better understand the impact of polarization on democracy, this chapter unpacks polarization into two key psychological components: (1) identification with one’s in-party, and (2) animosity toward an out-party. We summarize evidence on these positive and negative facets of attachment to a political party, which fuel democratic engagement but also motivate support for undemocratic practices. Out-party animosity, linked to but distinguishable from partisan identity, can promote more extreme antidemocratic behaviors, including support for political violence. We discuss implications of these dynamics for democratic backsliding in the United States and conclude that strong partisans are more concerned about their party than democracy.

Many factors influence the perceptions, attitudes and behaviour of actors in co-management, from trust and perceptions of legitimacy to the timing and extent of participation. The chapter introduces and reviews concepts that have less extensively been applied to analyses of the co-management of renewable natural resources. These concepts are personal values, behaviour, social norms, identity and agency. The chapter draws on literature from social psychology and philosophy to identify key characteristics of each concept and identify what has been learnt from application of these concepts to relevant contexts to the co-management of renewable natural resources. The chapter concludes by identifying key and recurring themes, particularly related to the need to understand the social context of co-management, the role of social norms and the links between values, behaviour, identity and agency and the rights and pursuits of justice of Indigenous Peoples and local communities involved in co-management.

This chapter critically assesses the identity approach to intergroup relations, which includes social identity theory and self-categorization theory. The identity approach has become the most important approach to understanding intergroup relations. The history of the identity approach is discussed, with a focus on Henri Tajfel, John Turner, and the European movement to establish a more social social psychology. Social identity theory proposes that people have a need for a positive and distinct identity, and experimental evidence testing this proposition is critcally discussed. The consequences of people feeling they have an inadequate social identity are also examined, with a focus on the conditions (e.g., perceived legitimacy and stability of the socio-political system) that lead to different types of individual and collective actions. The applied implications of the identity approach, and the relationship between this approach and other intergroup theories, are also examined.

The expansion of developer-funded archaeology in Britain since 1990 has generated a wealth of information about the rural settlement and landscape of Roman Britain. Using the rich dataset pulled together by the ‘Rural Settlement of Roman Britain’ project, this paper highlights several key elements of the distribution, type and morphology of the multitude of known settlements of this period, with reflections provided on the agricultural economy and the social identities of the people who lived in these places.

This chapter focuses on Alcibiades’ love–hate relationship with the people of Athens to explore the notion of hybris in the context of leadership. Drawing on the social identity theory of leadership, I argue that the Athenians’ ambivalent attitude towards Alcibiades was a result of his complex interaction with two central aspects of Athenian social identity. Insofar as the Athenians perceived themselves as an imperialist and aristocratic city, Alcibiades was a ‘prototypical’ Athenian in that he embodied and articulated the most extreme form of Athenian imperialism. Insofar as the Athenians perceived themselves as ‘middling’ citizens, however, Alcibiades’ private and public conduct (couched by Thucydides in the language of transgression and hybris) was an affront to the dominant egalitarian political ethos. The analysis of Alcibiades’ mutable relationship with the Athenian people highlights the ways in which a leader’s hybris can manifest itself and how it can impact negatively on the leadership process.

Volume I offers a broad perspective on urban culture in the ancient European world. It begins with chronological overviews which paint in broad brushstrokes a picture that serves as a frame for the thematic chapters in the rest of the volume. Positioning ancient Europe within its wider context, it touches on Asia and Africa as regions that informed and were later influenced by urban development in Europe, with particular emphasis on the Mediterranean basin. Topics range from formal characteristics (including public space), water provision, waste disposal, urban maintenance, spaces for the dead, and border spaces; to ways of thinking about, visualising, and remembering cities in antiquity; to conflict within and between cities, economics, mobility and globalisation, intersectional urban experiences, slavery, political participation, and religion.