Do advisers affect foreign policy and, if so, how? Recent scholarship on elite decision making prioritizes leaders and the institutions that surround them, rather than the dispositions of advisers themselves. We argue that despite the hierarchical nature of foreign policy decision making, advisers’ predispositions regarding the use of force shape state behavior through the counsel advisers provide in deliberations. To test our argument, we introduce an original data set of 2,685 foreign policy deliberations between US presidents and their advisers from 1947 to 1988. Applying a novel machine learning approach to estimate the hawkishness of 1,134 Cold War–era foreign policy decision makers, we show that adviser-level hawkishness affects both the counsel that advisers provide in deliberations and the decisions leaders make: conflictual policy choices grow more likely as hawks increasingly dominate the debate, even when accounting for leader dispositions. The theory and findings enrich our understanding of international conflict by demonstrating how advisers’ dispositions, which aggregate through the counsel advisers provide, systematically shape foreign policy behavior.

How do cognitive biases relevant to foreign policy decision making aggregate in groups? Many tendencies identified in the behavioral decision-making literature—such as reactive devaluation, the intentionality bias, and risk seeking in the domain of losses—have been linked to hawkishness in foreign policy choices, potentially increasing the risk of conflict, but how these “hawkish biases” operate in the small-group contexts in which foreign policy decisions are often made is unknown. We field three large-scale group experiments to test how these biases aggregate in groups. We find that groups are just as susceptible as individuals to these canonical biases, with neither hierarchical nor horizontal group decision-making structures significantly attenuating the magnitude of bias. Moreover, diverse groups perform similarly to more homogeneous ones, exhibiting similar degrees of bias and marginally increased risk of dissension. These results suggest that at least with these types of biases, the “aggregation problem” may be less problematic for psychological theories in international relations than some critics have argued. This has important implications for understanding foreign policy decision making, the role of group processes, and the behavioral revolution in international relations.

Canonical models of costly signaling in international relations (IR) tend to assume costly signals speak for themselves: a signal's costliness is typically understood to be a function of the signal, not the perceptions of the recipient. Integrating the study of signaling in IR with research on motivated skepticism and asymmetric updating from political psychology, we show that individuals’ tendencies to embrace information consistent with their overarching belief systems (and dismiss information inconsistent with it) has important implications for how signals are interpreted. We test our theory in the context of the 2015 Joint Comprehensive Plan of Action (JCPOA) on Iran, combining two survey experiments fielded on members of the American mass public. We find patterns consistent with motivated skepticism: the individuals most likely to update their beliefs are those who need reassurance the least, such that costly signals cause polarization rather than convergence. Successful signaling therefore requires knowing something about the orientations of the signal's recipient.

Despite a plethora of theoretical frameworks, IR scholars have struggled with the question of how observers assess resolve. We make two important contributions in this direction. Conceptually, we develop an integrative framework that unites otherwise disconnected theories, viewing them as a set of heuristics actors use to simplify information-rich environments. Methodologically, we employ a conjoint experiment that provides empirical traction impossible to obtain using alternative research designs. We find that ordinary citizens are ‘intuitive deterrence theorists’ who focus to a great extent on capabilities, stakes, signals and past actions in judging resolve. We also find that observers see democracies as less resolved than autocracies (not more), casting doubt on key propositions of democratic credibility theory. Finally, a conceptual replication shows that a group of elite decision makers converge with the US public in how they interpret costly signals, and in viewing democracies as less resolved than autocracies.

Politicians frequently turn to reputational arguments to bolster support for their proposed foreign policies. Yet despite the prevailing belief that domestic audiences care about reputation, there is very little direct evidence that publics care about reputation costs, and very little understanding of how. We propose a dispositional theory of reputation costs in which citizens facing ill-defined strategic situations turn to their core predispositions about foreign affairs in order to weigh competing reputational dimensions. Employing a diverse array of methodological tools—from vignette-based survey experiments to automated text analysis—we show that the mass public has a “taste” for reputation, but understands it in fundamentally different ways, with hawks concerned about the negative reputational consequences of inconsistency, and doves equally concerned with the negative reputational consequences of belligerence and interventionism. In illustrating how reputation costs are in our heads, our findings offer both good and bad news for theories of reputation in IR.

Why do some actors in international politics display remarkable persistence in wartime, while others “cut and run” at the first sign of trouble? I offer a behavioral theory of resolve, suggesting that variation in time and risk preferences can help explain why some actors display more resolve than others. I test the theory experimentally in the context of public opinion about military interventions. The results not only help explain why certain types of costs of war loom larger for certain types of actors but also shed light on some of the behavioral revolution's contributions more broadly.

Psychology is traditionally used in political science to explain deviations from rationality. Lost in the debate between rationalists and their critics, however, is a sense of whether the kinds of strategic self-interested behavior predicted by these models has psychological microfoundations: what would homo economicus look like in the real world? We argue that strategic rationality varies across individuals and is characterized by a pro-self social-value orientation and a high level of epistemic motivation. Testing our argument in the context of international relations, we employ a laboratory bargaining game and integrate it with archival research on German foreign policy-making in the 1920s. We find in both contexts that even among those interested in maximizing only their own egoistic gains, those with greater epistemic motivation are better able to adapt to the strategic situation, particularly the distribution of power. Our results build a bridge between two approaches often considered to be antithetical to one another.

Behavioral economics has shown that people often diverge from classical assumptions about self-interested behavior: they have social preferences and are concerned about issues of fairness and reciprocity. Social psychologists show that these preferences vary across actors, with some displaying more prosocial value orientations than others. Integrating a laboratory bargaining experiment with original archival research on Anglo-French and Franco-German diplomacy during the interwar period, the authors show how fairness and reciprocity matter in social interactions. That prosocials do not exploit their bargaining leverage to the degree that proselfs do helps explain why some pairs of actors are better able to avoid bargaining failure than others. In the face of consistent egoism on the part of negotiating partners, however, prosocials engage in negative reciprocity and adopt the same behaviors as proselfs.