Whether we realise it or not, many actors in international relations already apply psychology—however imperfectly—when trying to predict how other actors will behave. The problem is that these efforts are often piecemeal, inconsistent and lacking in psychological sophistication. What is needed is deeper collaboration between psychologists, political scientists and policymakers, combining strategic empathy with empirical research to create more accurate models of leadership behaviour.
In international relations, we devote enormous energy to understanding states, but the decisions that shape global politics are ultimately made by individuals. World leaders all bring their own personalities, biases and motivations to the negotiating table. By understanding the psychology of those leaders, we can better anticipate and interpret their behaviour.
Psychologists have long debated the ethics and legitimacy of psychoanalysing someone they have never met. Clinical diagnoses require direct interaction, and any psychological assessment from afar inevitably involves speculation. This challenge is compounded by the fact that political leaders rarely act alone, but rather in cooperation with advisory circles, cabinets or regimes.
But policymakers and analysts already engage in informal psychological profiling. These assessments often emerge under pressure, shaped as much by intuition and political context as by evidence. Yet, without a systematic framework, they risk reinforcing bias more than revealing insight.
The same issue extends to public commentary, where psychological labels are used loosely and without clinical grounding. You may have heard people call US President Donald Trump a ‘narcissist’ or label Russian President Vladimir Putin as ‘paranoid’, for example, without any diagnostic basis. This casual misuse not only dilutes the meaning of these terms but can also distort our understanding of leaders’ motivations.
If these assessments are being made anyway, they should be informed by genuine expertise. Bringing psychologists and international relations specialists into closer conversation could improve the accuracy of our assessments and reduce reliance on superficial stereotypes. Psychological insights should complement traditional IR tools and frameworks to enhance situational understanding.
Traditional foreign policy analysis often focuses on ideology, party politics or institutional incentives—areas that align closely with social psychology’s exploration of group behaviour, identity and collective influence. Social psychology already plays a quiet but important role in international relations, shaping how we understand norms, alliances and intergroup dynamics. Yet these frameworks can only take us so far. The individuals at the centre of power do not always conform to the expectations of their institutions or societies. Personality psychology offers a lens for understanding those deviations—cognitive styles, emotional needs and personal tolerances for risk that can drive leaders to act in ways no model of collective behaviour can fully predict.
This takes centre stage when the rational-actor model—the idea that states and leaders will always act in logically rational ways—breaks down. Rationality itself is subjective. It is shaped by one’s beliefs, experiences and worldview. What appears irrational from the outside may, within a leader’s personal frame of reference, be entirely coherent. For example, before Russia’s invasion of Ukraine, many analysts believed that Russian President Vladimir Putin was unlikely to conduct such an operation, believing it to be a strategic miscalculation. However, his decision aligned with a worldview rooted in grievance, historical destiny and perceived Western encirclement. Understanding such underlying beliefs can give analysts a clearer picture of how a leader might interpret a crisis or respond to provocation.
Research in personality psychology, though still sparse in the context of foreign policy, offers promising tools. Characteristics commonly known as the ‘big five’ traits—openness, conscientiousness, extraversion, agreeableness and neuroticism—are widely recognised as fundamental dimensions of personality and have been linked to distinct foreign policy attitudes. For instance, high openness might correlate with cooperative internationalism, while high neuroticism could predict more isolationist or defensive postures. While this research is still very early in its development, these effects appear relatively consistent across cultural and national contexts, suggesting they can provide meaningful insights even without direct access to leaders.
Moreover, certain patterns in how people think and make decisions can help explain why leaders sometimes make choices that seem illogical or persist with policies that are clearly failing. History offers no shortage of examples: from US president John F Kennedy’s ill-fated Bay of Pigs invasion to Putin’s gamble in Ukraine, overconfidence and risk tolerance have often driven decisions that appeared strategically sound only to those making them. Others, such as US president Lyndon Johnson in Vietnam, became trapped by their own need for consistency—escalating commitments rather than reversing course. Different kinds of leaders also thrive in different conditions: British prime minister Winston Churchill’s defiant temperament was indispensable in wartime but less suited to peacetime, while reformers such as Soviet Union president Mikhail Gorbachev flourished only until the systems they sought to soften turned against them.
If personality influences how individuals approach foreign policy—and the evidence suggests that it does—then ignoring it is a strategic blind spot. At a time when individual leaders wield enormous influence over global security, understanding the people behind the policies is a necessity.