What is confirmation bias?
There is overwhelming scientific consensus that climate change is real, important, and human-caused. So why do many remain skeptical about climate change, or unmotivated to reduce its impact?
Confirmation bias is the tendency to notice, pay attention to, or give more credibility to information that fits with our existing beliefs. This can lead us to make poor decisions by distorting our reasoning and judgment.
Confirmation bias happens in everyday life. When we are blind to the flaws of our friends, but can only see the flaws of our rivals. When a judge gives a sentence based on how they categorize the defendant. When a doctor looks for symptoms to confirm the diagnosis they suspect. Confirmation bias happens whenever we jump to interpret evidence as supporting what we already think, and discount evidence that contradicts it. Confirmation bias tends to be stronger for emotionally charged topics.
Research shows that confirmation bias can influence how we make sense of information about the climate crisis.
- Bias in gathering information: We tend to consume media or news that support our existing worldviews. For instance, while climate activists may focus on news articles about the impacts of climate change, climate skeptics may focus on articles that challenge climate change.
- Bias in interpretation: Given the same information, two people may reach different conclusions based on different interpretations. For example, while climate activists may interpret extreme weather events as proof of climate change, climate skeptics may view them as proof that weather is unreliable, and that therefore climate predictions are unreliable.
- Bias in memory: We tend to selectively remember information in a way that supports our expectations. An example: While climate activists may remember a previous heatwave in their city as hotter and more unusual than it was, climate skeptics may remember the same heatwave as not noteworthy.
Confirmation bias in the climate crisis
Human brains have evolved to pay attention to information important for our survival and reproduction. This means our brains had to become efficient at quickly filtering large amounts of information and predicting immediate threats.
To save time and effort in processing information, our brains developed mental shortcuts (sometimes called “heuristics”). These shortcuts helped our ancestors survive, but in the modern-day they often cause errors that distort reasoning and decision-making, known as cognitive biases.
Confirmation bias is one of these cognitive biases.
The history: The ancient Greek historian Thucydides described confirmation bias nearly 2500 years ago, writing that people “entrust to careless hope what they long for, and…use sovereign reason to thrust aside what they do not fancy”. It was not until the 1960s, however, that the term confirmation bias was coined by cognitive psychologist Peter Wason. He conducted a series of experiments showing that participants tended to confirm their first hypothesis rather than trying to test alternative hypotheses.
In the climate crisis: Cognitive biases, including confirmation bias, make it difficult to address multivalent, long-term, abstract issues such as the climate crisis. There has been global scientific understanding of the reality and importance of climate change for more than three decades, with the Intergovernmental Panel on Climate Change (IPCC) forming in 1988 and the first Earth Summit held in 1992. To understand why some people remain unconvinced about the reality or threat of climate change, researchers began studying the psychological barriers that inhibit climate belief and action.
George Marshall, author of Don’t Even Think About It: Why Our Brains are Wired to Ignore Climate Change, describes how confirmation bias impacts climate belief: “[Climate change] lends itself to multiple interpretations of causality, timing, and impact. This leaves it extremely vulnerable to our innate disposition to select or adapt information so that it confirms our pre-existing assumptions—biased assimilation and confirmation bias. If climate change can be interpreted in any number of ways, it is therefore prone to being interpreted in the way that we choose”.
Confirmation bias can distort our reasoning about the climate crisis, but the good news is that becoming aware of it helps. Awareness of confirmation bias has led people to develop better strategies to communicate climate change to a wider audience.
Differences in biases between different people
Everyone can be affected by confirmation bias, but different people will be affected in different ways. This is because different people have different pre-existing beliefs that will alter their perceptions of climate change. Pre-existing beliefs can be influenced by race, income, gender, political ideology, and education.
- In the United States, racial and ethnic minority groups show higher perceptions of climate change risks than white Americans, as do people with low income compared to those with high income.
- Cross-nationally, women report greater belief in and concern for climate change than men.
- Political affiliation (identification with political parties) is highly correlated (linked) with climate change belief in the United States, with 89% of Democrats viewing global warming as mainly due to human activities, but only 35% of Republicans.
- The correlation, or link, between political affiliation and climate change belief is much weaker in non-English speaking nations. This suggests that political orientation may not contribute to confirmation bias for all groups of people.
What more might we need to know?
Confirmation bias can be amplified by social media. Researchers have found that social media platforms like Twitter and Facebook may facilitate our tendency towards confirmation bias by allowing us to follow individuals, news sources, or forums that reflect our own opinions–a phenomenon coined echo chambers. Echo chambers can also be created by search engines like Google: The filter bubble effect describes how search results change depending on the history of the user.
Confirmation bias acts along with other cognitive biases. Climate change is challenging because it engages multiple biases that impact how we make sense of climate change, including:
- Hyperbolic discounting, which describes the tendency of people to value immediate rewards over longer-term rewards, even when the immediate rewards are smaller than the longer-term rewards.
- Loss aversion, which refers to people’s preference to avoid losses, rather than getting an equivalent gain. In other words, the pain of losing $100 is more powerful than the pleasure of gaining $100.
- Status quo bias, which describes people’s preference to leave things the way they are rather than changing them, because change may require effort and uncertainty.
Consequences if we don’t reduce carbon emissions drastically
Confirmation bias can prevent us from accepting the reality and threat of the climate crisis. It may also deepen the divisions among people around belief in climate change.
Mitigating the impacts of climate change requires bringing people together and taking cooperative action. To build collective belief in climate change, we need to develop not only an understanding of our own biases, including confirmation biases, but also tolerance and acceptance of different viewpoints.
- In the United States, people who believed in the existence and threat of global warming were more likely to remember the summer of 2010 as being warmer than normal compared to people who believed that global warming wasn’t happening or wasn’t a threat.
- Personal experience of the severe flooding in the United Kingdom in 2013/2014 increased perceived threat from climate change in people who attributed the flooding to climate change. However, for people who did not link the flooding to climate change, the personal experience of the flooding did not change whether they viewed climate change as a threat.
- Farmers in the Marlborough and Hawke’s Bay regions of New Zealand who believe that climate change is happening and is caused by human activities are more likely to perceive temperature increases than farmers who do not believe climate is happening or is not due to human activities.
- News media preferences are related to climate change beliefs. People selectively expose themselves to news media consistent with their worldview, which can reinforce their pre-existing beliefs about climate change.
- People pay attention to climate information differently depending on their political orientation. An eye-tracking experiment showed that self-identified liberals in British Columbia were more likely to focus on the rising phase of a graph of annual global temperature change, while those who self-identified as conservative were more likely to focus on the flat phase of the graph.
Counteracting confirmation bias
Cognitive biases are generally subconscious and automatic, meaning that we are not usually aware of how they influence our thought processes. The first step to addressing confirmation bias, therefore, is becoming aware of how it works and when it can happen.
At an individual level, other strategies include:
- Actively consider a range of alternative views. This can be achieved by seeking different sources of information or having conversations with people who hold differing opinions.
- Try to become aware of the basis upon which your opinions are founded. Noticing emotional responses to controversial issues might indicate the vulnerabilities of your belief system and potential moments of increased bias.
At a systemic level, researchers have developed several tools to address the cognitive biases of climate change. Some common tools include:
- Framing, which involves describing climate change in line with peoples’ value systems. For example, climate change poses both environmental risks (loss of biodiversity, ocean acidification, wildfires) and public health risks (increase in heat and respiratory illnesses, change in vector-borne diseases, mental health consequences). Some people are more concerned about climate change when it is framed as an environmental risk, whereas others are more concerned when it is framed as a public health risk.
- Reconstruction, which involves reconstructing an accurate representation of the social norms of a group by exposing people to views of in-group and out-group members. This can help in two ways: by encouraging people to consider alternative viewpoints, and by shifting the social norms that influence peoples’ decision-making.
- Using green defaults, which involves making climate-friendly options the status quo. This may reduce the effort of decision-making and therefore reduce the need for cognitive biases like confirmation bias.
While it might be impossible to eliminate cognitive biases, reducing them can help us more accurately understand the impacts of climate change, communicate about the climate, and promote collective action.
“Yes, he says, we’re wired to ignore climate change,” a Washington Post review of George Marshall’s Don’t Even Think About It reminds us, “But we’re also wired to do something about it”.
Don’t Even Think About It: Why our Brains are Wired to Ignore Climate Change, by George Marshall, published in 2014 by Bloomsbury Publishing.
Thinking, Fast and Slow, by Daniel Kahneman, published in 2011 by Farrar, Straus and Giroux.
The Psychology of Climate Change Communication: A Guide for Scientists, Journalists, Educators, Political Aides, and the Interested Public, by Debika Shome and Sabine Marx, published in 2009 by the Center for Research on Environmental Decisions at Columbia University.
Articles and Online Sources
Confirmation bias: believing what you see, seeing what you believe, published in Ness Labs by Anne-Laure Le Cunff.
How brain biases prevent climate action, published in BBC Future on March 8, 2019, by Matthew Wilburn King.
Stop making sense: why it’s time to get emotional about climate change, published in The Guardian on July 4, 2020, by Rebecca Huntley.
Understand faulty thinking to tackle climate change, published in New Scientist on August 13, 2014, by George Marshall.
Why do we favor our existing beliefs?, published in The Decision Lab.
Why our brains are wired to ignore climate change, published in The Washington Post on August 21, 2014, by Matthew Huston.
Beware online “filter bubbles”, a TED talk given by Eli Pariser, May 2, 2011.
Climate Change and Cognitive Biases, published in CBT Professionals on September 24, 2020, by Dr. Adrian Ashton.
Selected Research/Scientific Papers
Bolin, J. L., & Hamilton, L. C. (2018). The News You Choose: news media preferences amplify views on climate change. Environmental Politics, 27(3), 455-476. https://doi.org/10.1080/09644016.2018.1423909
Cinelli, M., De Francisci Morales, G., Galeazzi, A., Quattrociocchi, W., & Starnini, M. (2021). The echo chamber effect on social media. Proc Natl Acad Sci U S A, 118(9). https://doi.org/10.1073/pnas.2023301118
Drummond, C., & Fischhoff, B. (2017). Individuals with greater science literacy and education have more polarized beliefs on controversial science topics. Proc Natl Acad Sci U S A, 114(36), 9587-9592. https://doi.org/10.1073/pnas.1704882114
Hornsey, M. J., Harris, E. A., & Fielding, K. S. (2018). Relationships among conspiratorial beliefs, conservatism and climate skepticism across nations. Nature Climate Change, 8(7), 614-620. https://doi.org/10.1038/s41558-018-0157-2
Howe, P. D., & Leiserowitz, A. (2013). Who remembers a hot summer or a cold winter? The asymmetric effect of beliefs about global warming on perceptions of local climate conditions in the US. Global Environmental Change-Human and Policy Dimensions, 23(6), 1488-1500. https://doi.org/10.1016/j.gloenvcha.2013.09.014
Kahan, D. M., Peters, E., Wittlin, M., Slovic, P., Ouellette, L. L., Braman, D., & Mandel, G. (2012). The polarizing impact of science literacy and numeracy on perceived climate change risks. Nature Climate Change, 2(10), 732-735. https://doi.org/10.1038/Nclimate1547
Luo, Y., & Zhao, J. Y. (2021). Attentional and perceptual biases of climate change. Current Opinion in Behavioral Sciences, 42, 22-26. https://doi.org/10.1016/j.cobeha.2021.02.010
Nickerson, R. S. (1998). Confirmation Bias: A Ubiquitous Phenomenon in Many Guises. Review of General Psychology, 2(2), 175-220. https://doi.org/https://doi.org/10.1037/1089-2622.214.171.124
Niles, M. T., & Mueller, N. D. (2016). Farmer perceptions of climate change: Associations with observed temperature and precipitation trends, irrigation, and climate beliefs. Global Environmental Change-Human and Policy Dimensions, 39, 133-142. https://doi.org/10.1016/j.gloenvcha.2016.05.002
Norgaard, K. M., & World Bank. (2009). Cognitive and behavioral challenges in responding to climate change. World Bank. http://econ.worldbank.org/external/default/main?pagePK=64165259&theSitePK=469372&piPK=64165421&menuPK=64166093&entityID=000158349_20090519142931
Ogunbode, C. A., Demski, C., Capstick, S. B., & Sposato, R. G. (2019). Attribution matters: Revisiting the link between extreme weather experience and climate change mitigation responses. Global Environmental Change, 54, 31-39. https://doi.org/10.1016/j.gloenvcha.2018.11.005
Pearson, A. R., Ballew, M. T., Naiman, S., & Schuldt, J. P. (2017). Race, Class, Gender and Climate Change Communication. Oxford Research Encyclopedia of Climate Science. https://doi.org/10.1093/acrefore/9780190228620.013.412
Zhao, J., & Luo, Y. (2021). A framework to address cognitive biases of climate change. Neuron, 109(22), 3548-3551. https://doi.org/10.1016/j.neuron.2021.08.029
September 22, 2022
Author: Colleen Rollins, PhD, Neuroscience, Cambridge University
Editor: Rei Takver