This manuscript examines how growing up with a sibling relates to prosociality and how knowledge of a partner’s sibling background may serve as a behavioral cue. In a series of experimental games, we found that individuals with siblings were significantly more likely to cooperate in stag hunt and contribute more in public goods and dictator games than only children (OC) on average. In two treatments where a sibling status cue is exogenously revealed, only-child pairs exhibited reduced prosociality. OC exhibit different empirical expectations of behavior compared to those with siblings, while generally sharing the same normative beliefs. Language AI analysis of subjects’ written perspectives on the games corroborates these patterns. We conclude that OC exhibit more context-dependent prosociality, with behavior more closely aligned with empirical expectations than normative beliefs, a pattern not observed in those with siblings.

If change is the only constant, how does the law keep pace with technology? Without a centralized judiciary, international law should be especially susceptible to disruption, yet it can be remarkably resilient in practice. I argue that efforts to minimize legal ambiguity, long seen as integral to compliance, can hinder its application to new technologies. Drawing on first principles from psycholinguistics, my theory differentiates between what I call convergent and divergent forms of flexibility. Unlike divergent flexibility, which gives rise to contestation, convergent flexibility tends to promote consensus, even when (1) technology is unprecedented and (2) regulatory interests sharply diverge. To test the theory, $450$ trained legal professionals were commissioned to take part in a randomized controlled trial (RCT) that varied technological novelty, legal precision, and political incentives. Participants collectively contributed 280,000 words over 10,000 hours in defense of their professional legal opinions, offering a novel (agent-subjective) measure of compliance. To establish external validity, the experiment is complemented with research into the legal impact of two breakthrough chemical weapons technologies: “super tear gas” and novichok. The findings contribute a general theoretical framework for understanding when and why emerging technologies are legally disruptive.

Existing accounts of normative change in international politics place undue focus on powerful actors as norm entrepreneurs and the organizational platforms that facilitate their advocacy. This can obscure the ideational innovation that precedes advocacy, biasing analysis towards structural incentives, rather than agency. To rebalance such accounts, we offer an agentive model of ideational innovation that treats norm entrepreneurship as a process, rather than locating it in a single actor. By bridging IR and history of political thought, our model helps trace the origins of normative ideas, development, and influence forensically. We illustrate its benefits with multi-archival research (conducted in the US, UK, and Czechia) into Bohuslav Ečer, Czechoslovakia’s representative at the 1943–1948 UN War Crimes Commission. Employing process tracing methods on new evidence, we show how Ečer synthesized multiple influences into an innovative proposal for holding individuals criminally responsible for aggression. Using original archival documents, we show how his ideas swayed key US policymakers via unlikely channels and helped shape a pivotal international norm codified in the 1945 Nuremberg Charter. Appreciation of Ečer’s agency alongside other key innovators contributes to our understanding of a pivotal norm, helps remedy biases in knowledge production, and enriches our theoretical understanding of normative change.

A growing body of work suggests that authoritarian regimes can enhance their external legitimacy by undertaking reform—from democratic or “pseudodemocratic” institutional changes at the domestic level to participation in international efforts to mitigate climate change. Yet the shared theoretical logic underlying this work has received surprisingly little empirical attention. This research contributes by offering findings from an iterative series of original survey experiments conducted over nationally representative samples of US citizens. Study 1 tested the foundational hypothesis—that reforms build external legitimacy—by adopting a simple independent groups design. Studies 2 and 3 subjected that hypothesis to harder tests via conjoint designs, and also evaluated extension hypotheses about when and in what sense “legitimacy” is gained. Across studies, the results consistently demonstrate that reforms (of a variety of types) do generate external legitimacy, offering both positive benefits as well as shielding benefits in keeping with theoretical arguments. The results also provide support for several new and previously undocumented findings concerning the role of reform type, type of legitimacy-derived gain, and the conditions under which such gains are more or less likely to accrue.

This paper presents a logic programming-based framework for policy-aware autonomous agents that can reason about potential penalties for noncompliance and act accordingly. While prior work has primarily focused on ensuring compliance, our approach considers scenarios where deviating from policies may be necessary to achieve high-stakes goals. Additionally, modeling noncompliant behavior can assist policymakers by simulating realistic human decision-making. Our framework extends Gelfond and Lobo’s Authorization and Obligation Policy Language ($\mathscr{AOPL}$) to incorporate penalties and integrates Answer Set Programming (ASP) for reasoning. Compared to previous approaches, our method ensures well-formed policies, accounts for policy priorities, and enhances explainability by explicitly identifying rule violations and their consequences. Building on the work of Harders and Inclezan, we introduce penalty-based reasoning to distinguish between noncompliant plans, prioritizing those with minimal repercussions. To support this, we develop an automated translation from the extended $\mathscr{AOPL}$ into ASP and refine ASP-based planning algorithms to account for incurred penalties. Experiments in two domains demonstrate that our framework generates higher-quality plans that avoid harmful actions while, in some cases, also improving computational efficiency. These findings underscore its potential for enhancing autonomous decision-making and informing policy refinement.

Policy makers can use four different modes of governance: ‘hierarchy’, ‘markets’, ‘networks’ and ‘persuasion’. In this article, it is argued that ‘nudging’ represents a distinct (fifth) mode of governance. The effectiveness of nudging as a means of bringing about lasting behaviour change is questioned and it is argued that evidence for its success ignores the facts that many successful nudges are not in fact nudges; that there are instances when nudges backfire; and that there may be ethical concerns associated with nudges. Instead, and in contrast to nudging, behaviour change is more likely to be enduring where it involves social identity change and norm internalisation. The article concludes by urging public policy scholars to engage with the social identity literature on ‘social influence’, and the idea that those promoting lasting behaviour change need to engage with people not as individual cognitive misers, but as members of groups whose norms they internalise and enact.

Huntington's third wave of democracy was no such thing. It neither ushered in a democratic era nor was it a wave in any acceptable historical sense. What it did do was to highlight a contrast and competition among norms and values, so that what we automatically regard as undemocratic practice that is norm-free is no such thing. They might perhaps, and with a freight of contingencies, be bad norms—but they are still norms.

NGOs are recognized as active participants in the policy process. There is general agreement that they are agenda setters and important actors in the framing of public issues. They are well-recognized providers of social services on behalf of, or in partnership with, private and public actors. Previous research demonstrates that the institutional context accounts for the extent of NGOs’ access to and influence over public policy making. Nonetheless, we know less about why there are important differences in the way they approach the policy process. Comparing the organizational evolution of two Spanish NGOs, both active in the field of humanitarian aid and poverty alleviation over a period of more than 50 years, this article contributes to our understanding of the relevance of organizational structure in NGOs as a determining factor in their role in public policy. Drawing on institutional organizational analysis, a theoretical framework is developed to assess the importance of organizational structure in explaining why NGOs take on different roles in the policy process, even when sharing the same institutional context. NGOs are driven by pre-existing institutions and legacy that affect the way they resolve conflict and engage in internal bargaining.

Norm contestation has become a defining characteristic of our time and a major interest in International Relations (IR) scholarship. However, researchers often view contestation as a repudiation of norm socialization and thus overlook the ways in which contestation occurs within socialization. This article advances an interpretive account based on performativity to capture the role of cultural translation and appropriation as practices of contestation within processes of norm socialization. It makes three key interventions. First, it redefines norm socialization as a process of cultural translation rather than straightforward transition. Second, it investigates various strategies through which actors appropriate norms by disjointing a norm’s normative appeal from its normalizing power – its prevalent interpretation. Third, it underscores how such contestations destabilize the relationships of authority and hierarchy in normative engagements. To illustrate the analytical purchase of this framework, the paper analyses the Egyptian Muslim Brotherhood’s discourses of ‘Islamic democracy’ and the ‘Islamic civil state’ as examples of their performative socialization into the norm of democracy. The paper concludes by reflecting on the democratic promise as well as the precariousness of performative socialization in world politics.

United Nations peacekeeping is drifting from its post–Cold War liberal model toward a more sovereignty-focused approach. This essay posits that the change is not formal or doctrinal, but instead emerges through institutional drift and norm reinterpretation, driven by accelerated US retrenchment, China and Russia’s growing influence, host-state assertiveness, and internal United Nations adaptation. Drawing on theories of norm dynamics, bureaucratic culture, and empirical studies of peacekeeping mission practice, the analysis shows how liberal principles, such as democratization and human rights, are increasingly sidelined in favor of conflict containment and host-state support. The essay concludes by outlining four potential futures for peacekeeping: gradual drift into stabilization, normative fragmentation and regionalization, niche reaffirmation of liberalism, and formal norm redefinition. Together, these scenarios suggest peacekeeping is entering a postliberal era, marked not by collapse, but by contested adaptation within a shifting world order.