This blog was written together with Dr. Jana-Maria Hohnsbehn and David F. Urschler.
When we form an opinion, we tend to look for evidence that confirms it and ignore evidence that challenges it. This tendency, known as confirmation bias, is one of the most pervasive and consequential cognitive biases identified by psychological research. It affects decisions in finance, where investors may cling to initial assessments and overlook warning signs; in science, where researchers may unconsciously favor results that support their hypotheses; in emergency medicine, where a first impression can cause clinicians to miss alternative diagnoses; and in criminal investigations, where early suspicion can unduly narrow the scope of inquiry. During the COVID-19 pandemic, confirmation bias contributed to the misinterpretation of epidemiological data and poor crisis management. It also fuels political polarization: research shows that both liberals and conservatives tend to avoid exposure to opposing viewpoints, forming ideological echo chambers that facilitate the spread of misinformation.
Given the breadth and severity of these consequences, identifying factors that reduce confirmation bias is both scientifically and practically important. We believe trait ambivalence is one such factor.
Trait Ambivalence: A Stable Tendency to See Both Sides
Ambivalence means holding both positive and negative evaluations of the same object simultaneously. A voter may support a candidate's economic policy while opposing their stance on environmental regulation. A consumer may value a product for its quality while feeling uneasy about the company's labor practices. Most research on ambivalence has examined it as a momentary state: a snapshot of mixed feelings experienced in a specific situation.
But people also differ in how often they experience ambivalence across situations. Some individuals habitually see multiple sides of issues, feel torn more frequently, and find it harder to settle on straightforward evaluations. This is what we call trait ambivalence: a stable individual tendency to experience ambivalence. Prior work from our lab showed that people high in trait ambivalence make more balanced social judgments and are less prone to the correspondence bias, the tendency to over-attribute others' behavior to their character rather than to situational circumstances (Schneider et al., 2021). If trait ambivalence promotes balanced judgment in person perception, it may also reduce the tendency to search for and favor information that confirms existing beliefs.
How We Tested This
We conducted five studies with a total of 1,306 participants, using different methods to capture different facets of confirmation bias.
In Studies 1A and 1B, participants completed a series of short decision tasks in which they could choose either a confirmatory or a disconfirmatory way to test an assumption — for example, whether a number sequence follows a particular rule. People higher in trait ambivalence were more likely to choose disconfirmatory strategies, challenging the assumption rather than looking for supporting evidence.
In Studies 2A and 2B, we used the Trait Hypothesis Testing Task (Snyder & Swann, 1978), a well-established paradigm in which participants imagine interviewing someone to determine whether that person is extroverted. They select from a list of confirmatory questions (e.g., “What do you like about parties?”), disconfirmatory questions (e.g., “In what situations do you wish you could be more outgoing?”), and neutral questions. People higher in trait ambivalence consistently selected fewer confirmatory and more disconfirmatory questions, suggesting they were less committed to confirming the initial hypothesis and more open to evidence that might contradict it.
Study 3 examined a different facet of confirmation: how people evaluate information once they have access to it. Participants read about a store manager’s performance and made a preliminary decision about whether to extend his contract. They were then presented with expert statements either supporting or opposing their decision. We measured how credible and important they rated each piece of information and whether they wanted to read more about it. People high in trait ambivalence showed a smaller evaluation bias: they rated confirmatory and disconfirmatory information more similarly, rather than systematically favoring arguments that aligned with their preliminary decision.
The Overall Picture
A meta-analysis across all studies, including three additional studies reported in supplementary materials (eight studies in total), confirmed a reliable negative relationship between trait ambivalence and confirmation bias (r = −0.17, p < .01). The more ambivalent by trait, the less confirmation bias individuals showed, and this held across different paradigms, different aspects of confirmation, and samples from the United States, the United Kingdom, and Germany.
We also examined whether experimentally inducing a momentary state of ambivalence would produce a similar effect. It did not: a manipulation in which participants wrote about an ambivalent topic produced no significant reduction in confirmation bias in the strategies people used. This suggests that the benefits we observed are linked specifically to the chronic, dispositional tendency to experience ambivalence, rather than to a transient ambivalent feeling. Interestingly, however, when participants felt ambivalent about the decision itself, this was associated with less confirmation in how they evaluated information, pointing to a more nuanced relationship between ambivalence and bias depending on whether the ambivalence directly concerns the decision at hand.
What This Means
Our findings contribute to a growing body of research that challenges the view of ambivalence as simply a problem to be resolved. In organizational and individual decision-making, where confirmation bias can lead to costly errors, trait ambivalence may function as a cognitive asset. People who are naturally disposed to hold competing evaluations and sit with complexity appear better equipped to consider a fuller range of evidence, actively seeking information that could falsify their working hypothesis rather than only that which confirms it.
This does not imply that decision-makers should cultivate indecision. Rather, it suggests that the genuine capacity to consider both sides of an issue — the psychological hallmark of trait ambivalence — may support higher-quality reasoning in precisely the contexts where confirmation bias does the most damage: complex decisions with high stakes and mixed evidence.