America is increasingly ideologically polarized, fueling intergroup conflict and intensifying partisan biases in cognition and behavior. To date, research on intergroup bias has predominantly examined biases in how people search for information and how they interpret information in isolation. Here, we integrate these two perspectives to elucidate how partisan biases manifest across the information processing stream, beginning with (1) a biased selection of information, leading to (2) skewed samples of information that interact with (3) motivated interpretations to produce evaluative biases. Across 3 empirical studies and 3 internal meta-analyses, participants freely sampled information about ingroup and outgroup members or ingroup and outgroup political candidates until they felt confident to evaluate them. Replicating our results across these different sampling environments, we reliably find that the majority of participants begin sampling information from their own group, which was associated with individual differences in group-based motives, and that participants sampled overall more information from their own group. This, in turn, generates more variability in ingroup (relative to outgroup) experiences that subsequently fall prey to motivated interpretations. We further demonstrate that participants employ different sampling strategies over time when the ingroup is de facto worse than the outgroup, and that they asymmetrically integrate information into their evaluations based on the congeniality of initial experiences. The proposed framework extends classic findings in psychology by connecting people’s early experiences to downstream evaluative biases and has implications for intergroup bias interventions.

Throughout life, people sometimes lie to curry favor or mitigate disharmony with others, a tendency that may be exacerbated under moments of elevated tension. This phenomenon is captured by the economic theoretical framework of Preference Falsification, which describes why people misrepresent their beliefs in the face of social pressures, and how misrepresentation accumulates to broader misunderstandings that can fuel political polarization. We describe why the current political climate may foster motivations to misrepresent beliefs, as individuals are increasingly siloed into like-minded communities with strong pressures to conform to group norms. Next, we adopt a psychological lens to understand and integrate three motivations that underlie individual misrepresentation – relating to an individual’s intrinsic preference, their reputational concern, and their desire for expression – and describe how individual acts of misrepresentation can propagate across social connections to establish misrepresented beliefs as public consensus. Finally, we outline inroads for examining Preference Falsification using psychological methods that may be uniquely suited to elucidate the different social dynamics and issues that elicit this behavior, with the goal of spurring future research. Ultimately, we argue that fostering a more ideologically pluralistic and socially interconnected society may offer one route to reducing misrepresentation and collective misunderstanding, and thereby attenuate polarization and intergroup antipathy.