New Insights on Voter-Party Congruence and Cognitive Ability: A Genetically Informed Approach

Political representation is a cornerstone of liberal democracy. A common way to assess it is to examine how closely citizens’ policy preferences align with those advocated by the parties they support. Cognitive ability is frequently invoked to explain variation in this voter–party congruence, with scholars typically assuming a positive effect. Yet, evidence for a causal link is not established. To address this, I use a genetically informed twin-pair fixed-effects design. The results show, first, that genes associated with cognitive ability influence voter–party congruence on several policy dimensions. However, additional analyses indicate that this effect is not always mediated by the cognitive ability trait itself, suggesting the presence of other individual-level characteristics that shape congruence. For the outcomes where a causal influence of cognitive ability does emerge, the evidence points to multiple underlying mechanisms rather than a single pathway, underscoring the complexity of how cognitive ability translates into political representation.