The evolutionary advantages and social pitfalls of confirmation bias

By Amanda N. Weiss

This is the first post on the big idea of confirmation bias.

In a world with an overwhelming abundance of information and opinions, it is no surprise that we do not take it all in and instead must devote our attention to a select subset of information . But, as with every instance of selective information-seeking,  we risk our cognitive biases preventing us from forming a well rounded and well reasoned mental model of the world. Confirmation bias, the tendency to seek out information that agrees with our beliefs and reject that which opposes them, is one such element of our psychology. I recently had a discussion with Dr. Tali Sharot, the director of the Affective Brain Lab at the University College London, about her work on the neuroscience of information-seeking and how it relates to confirmation bias. Dr. Sharot is especially interested in figuring out why we engage in behaviors that seem arational (not based on reason), as opposed to those with clear purposes.

Earlier this year, a study conducted by Kappes et al., with Dr. Sharot as corresponding author, was published in Nature Neuroscience that sought to examine the mechanisms of belief formation in the context of confirmation bias. Behaviorally, the research uncovered that people are more likely, when evaluating their own opinion, to consider the strength of another’s opinion only when it aligns with their own. Dr. Sharot’s team conducted functional magnetic resonance imaging (fMRI) to measure brain activity (based on changes of blood flow) in a brain region involved with reevaluating decisions upon new information gain. They learned that, similar to the behavioral trend, the brain region appears to track the strength of agreeing, but not dissenting, opinions

From a practical perspective, confirmation bias makes sense as a heuristic for modifying our mental models of the world around us. Most of the knowledge we have is shared amongst people and is in fact true; this applies to things as simple as ‘the sky is blue’ or ‘things that are tossed up will return down.’ As such, if we are confronted with someone telling us otherwise, it is in our best interest to reject their claims. In this way, confirmation bias, similarly to other cognitive biases, can offer an evolutionary advantage. This could explain why it has persisted over time. In fact, we see these cognitive biases in non-human animals as well. For instance, the optimism bias -- the belief that we, ourselves, are less likely to experience a negative event -- is conserved in almost every animal, ranging from primates all the way down to ants. Paraphrasing from Dr. Sharot, confirmation bias becomes problematic in only a small fraction of cases. However, these situations often attract our attention because they contribute to the polarization of groups that hold different beliefs within society. In extreme cases, usually those that are highly emotionally evocative, polarization of opinions can lead to violence and other severe effects in society. We often see polarization of ideas regarding sociopolitical beliefs in the present day.

With that in mind, you may wonder whether there are particular social factors that contribute to the apparent prevalence of confirmation bias and whether there are ways that we can reduce the problems that consequently arise. Though this bias has long been a part of our psychology, the recent near-ubiquity of social media and the associated ease of limiting our information intake has served to enhance this effect. When we selectively interact with social media posts expressing a particular opinion, algorithms built into the sites tend to present more related information, since it is likely to also grab your attention. Furthermore, we can decide to follow particular people while ignoring others. In Dr. Sharot’s words, social media enables us to more directly be “our agent of our own information.” Unlike in-person interactions in which abruptly leaving a conversation or ignoring someone altogether is a blatantly rude act, scrolling past or otherwise dismissing posts online is easy and largely free of etiquette consequences. As such, we can more effectively filter out information that we do not necessarily want to hear. This can build an atmosphere in which we do not even take other perspectives into consideration when making decisions.

Luckily, the challenge of avoiding the influence of our biases in cases where they are problematic has not gone unmet. Anti-bias training has been implemented in certain social structures, such as education systems. However, as many of these regimens tend to focus on bias awareness more so than avoidance, they are not always as effective as we hope.  In Dr. Sharot’s words, “awareness alone is not enough, but it is a first step”; when likening cognitive bias to optical illusions, even if we understand why the phenomenon happens, “the illusion doesn’t go away.” Instead, it is necessary to put anti-bias policies in place and enforce them; for instance, companies and universities could require that decision-making groups interact with people representing all major perspectives among the people affected by the choices they make. Additionally, on the individual level, working on metacognition can be helpful -- if people are able to reflect upon their own thinking such that their confidence better reflects their accuracy in decision-making, that can be helpful in preventing the negative effects of our biases. Furthermore, we can make an effort to expose ourselves to a variety of opinions online by disabling the personalized targeted advertisement algorithms that shape what we see and by having online connections with people who hold differing views.

Ultimately, we have to live with the fact that confirmation bias, among other cognitive biases, is an inherent aspect of the way we think. And while it is largely practical in daily life, we must recognize the cases where it limits our thinking, and then delve more deeply into all considerations before reaching a conclusion. As we broaden our social connections and the information that we access, we can avoid falling into the echo chambers that restrict the growth of our ideas.

References:

Heshmat S. 2015. What is Confirmation Bias? Psychology Today. https://www.psychologytoday.com/us/blog/science-choice/201504/what-is-confirmation-bias

Mandese J. 2020. Pew Affirms Media Confirmation Bias, American News Consumers More Polarized Than Ever. Marketing: Politics Weekly. https://www.mediapost.com/publications/article/346157/pew-affirms-media-confirmation-bias-american-news.html
Kappes A., Harvey A.H., Lohrenz T., Montague P.R., and Sharot, T. 2020 Confirmation bias in the utilization of others’ opinion strength. Nat Neurosci 23, 130–137.