필사 모드: Political Polarization — Why Are We Drifting Further Apart?

Opening: Why the Dinner Table Went Quiet

A holiday evening. A family gathers after a long time apart. Talk drifts over food and news of who is doing what. Then someone, carelessly, brings up politics. The air shifts. The mother tries to change the subject, an uncle's voice rises, a cousin retreats into a phone. Everyone knows it. This topic is dangerous.

Only a generation or two ago, turning your back on a relative over political disagreement was rare. People differed, but there was a sense that "politics is politics and people are people." Today, many feel something stronger than "I can't talk politics with that person." They feel: "I'd rather not be close to anyone who thinks like that."

This shift has a name: **political polarization**. The word is everywhere, yet it is surprisingly hard to assemble a clear picture of what it actually refers to, why it intensifies, and whether it is truly beyond repair.

This essay does not take the side of any party or ideology. That is the point. The best way to understand polarization is not to prove that your own camp is righteous, but to step back and examine the structure of the division itself. Let us follow that structure together.

1. Two Kinds of Polarization: What Is Actually Splitting?

The claim that "our society has polarized" actually bundles together two entirely different phenomena. Political scientists separate them into two strands.

Issue Polarization

The first is **issue polarization**, also called ideological polarization. It refers to people's positions on specific policy questions—taxes, welfare, immigration, the environment, security—spreading toward opposite extremes. The middle thins out, and people cluster at the two ends.

What is intriguing is that, across many studies, ordinary citizens' policy preferences have not spread to the extremes as much as we tend to assume. On many issues, most citizens remain distributed somewhere in the middle. In other words, much of the division we feel cannot be explained by "distance between our views on specific policies" alone.

Affective Polarization

This is where the second concept enters: **affective polarization**. This is not about disagreement over policy, but about growing **emotional hostility and dislike** toward the opposing camp. According to what political scientists have measured, in many societies, warmth toward the other side has fallen far more steeply than positions on policy have diverged.

Put simply: "I oppose that policy" is issue polarization. "I dislike the people who support that policy" is affective polarization. And what characterizes our era is the latter.

Why does this distinction matter? If the essence of division were policy distance, better information and debate could narrow the gap. But if the essence is emotional hostility, even the most accurate statistics may have no effect. Human beings instinctively resist conceding that someone they hate could be right.

The Two Polarizations at a Glance

Issue polarization Affective polarization

What splits Policy / ideology Feelings toward others

How measured Distribution of views Warmth / trust scales

Core question "What do you believe?" "Whom do you dislike?"

Cooling clue Information, deliberation Contact, empathy, de-stigma

Danger Gridlock, paralysis Distrust, hostility, decay

2. A Thought Experiment: The "Politically Colorblind" Society

Imagine, for a moment, a country where everyone suddenly lost the ability to see political "color." No one can tell who belongs to which camp or which party they support. People can only evaluate the concrete proposal itself.

A proposal arrives: "Let us spend budget repairing the border highway." Because no one knows which camp it came from, they weigh only the state of the road and the efficiency of the spending. They may still split for and against—but the split is about the road, not about "those people."

This experiment reveals that much of what we actually evaluate in real politics is not the proposal itself, but **the label attached to it**. The same policy gains support when "our side proposed it" and loses support when "their side proposed it"—a pattern observed repeatedly in experiments. Far more often than we admit, we judge by the source rather than the substance.

Of course, political colorblindness is impossible in reality. Parties and camps are also useful cognitive shortcuts that let us judge a complicated world quickly. We cannot research every issue from scratch on our own, so consulting the judgment of a trusted group is natural and efficient.

The trouble starts when that shortcut quietly replaces the entire road. When the label becomes not an aid but the sole criterion of judgment, we stop looking at the content of the proposal at all. A healthy political sense is not about discarding camps altogether, but closer to the ability to use the shortcut of a camp while occasionally pausing to ask yourself, "Is this judgment really based on the content?"

3. Why We Split: Four Engines

Affective polarization is not the result of any single cause. Several forces interlock and reinforce one another. Let us look at four major engines. I want to stress, first, that none of these is the fault of any particular camp. They are structural.

Engine 1: Politics as Identity

Humans are fundamentally group-forming animals. Social psychologist Henri Tajfel's classic experiments showed this with startling clarity. He divided people into two groups using utterly meaningless criteria—say, whether they overestimated or underestimated the number of dots in an image. The groups had no real stakes, no shared history. And yet people immediately began allocating resources to favor their own group.

This is the **minimal group paradigm**. Draw any line between "us" and "them"—however trivial—and humans will favor the in-group and grow wary of the out-group.

The more political identity overlaps with religion, ethnicity, region, and lifestyle, the stronger this effect becomes. When a political leaning becomes not merely "which policies I prefer" but part of "who I am," political opposition starts to feel like an attack on identity. That is why debates so easily curdle into personal attacks. We are not defending an idea; we are defending ourselves.

Researchers also call this "identity stacking." In the past, the same person often stood on one side of one issue and the other side of another. Politics, religion, region, and taste pointed in different directions, so you clicked with one friend on one topic and another friend on a different one. When the lines of identity cross one another like this, no one becomes a complete "enemy." But when those lines fold into one, with every identity aligned along the same partisan divide, the other person is no longer an opponent on a single issue but "the other in every respect." This alignment is the decisive condition for deepening hostility.

Engine 2: Media and Algorithms

The second engine is the window through which we see the world: media.

In the past, a small number of widely shared sources existed. When people watched the same news, they could at least share a common factual ground about "what happened." Opinions differed, but the starting point was the same.

Today's information environment is different. An endless number of channels and outlets report events through their own lens. And then come the **algorithms**. A recommendation algorithm's goal is not to convey truth but to maximize time on the platform. And what most powerfully holds human attention is often content that triggers anger and fear.

As a result, algorithms tend, unwittingly, to expose us more often and more intensely to signals that "our side is right and the other side is foolish or wicked." The algorithm is not deliberately dividing society. It simply shows what grabs attention—and our brains happen to find hostility fascinating.

This mechanism shows up in a few everyday experiences:

- A post that mocks the other side or expresses anger draws more reactions than a calm, balanced one.

- Once you linger on one camp's content, more and more similar content is recommended.

- The other camp's most foolish statement is repeatedly surfaced as a "representative case," distorting your impression of them as a whole.

The key is that this is not anyone's malice but the natural product of a system. So the remedy must begin not with "finding bad people" but with "how do we consciously handle the system?"

Engine 3: Echo Chambers and Confirmation Bias

The media environment builds **echo chambers**: spaces where like-minded people gather, trade the same statements, and repeatedly confirm the same conclusions. In an echoing room, only your own voice returns to you.

To this is added an old cognitive habit of the human mind: **confirmation bias**. We readily accept information that supports our existing beliefs and skeptically scrutinize or ignore information that contradicts them. It is why people can watch the same event and walk away with opposite lessons.

The longer we stay in an echo chamber, two things happen. First, our own camp's position looks ever more obvious and self-evident. Second, our picture of the other camp grows ever simpler and more extreme. We come to imagine not the most reasonable person on the other side, but the most extreme, as their representative.

Engine 4: The Design of Institutions and Elections

The final engine is often overlooked yet very powerful: **the design of institutions**.

Electoral systems, party structures, and decision rules create strong incentives for how political actors behave. In a winner-take-all structure, for instance, mobilizing your camp's most fervent supporters can be more effective than persuading moderate voters. And the easiest way to mobilize supporters is often to amplify "fear of the other side."

When institutions are designed to reward cooperation, politicians compromise; when they reward confrontation, politicians fight. To see polarization only as a matter of individual morality is to miss this structural dimension. The same people behave differently under different rules.

[The self-reinforcing loop of polarization]

Identity-fusion ──→ Rising hostility

↑ │

│ ↓

Institutional ←── Echo chambers /

incentives algorithms

↑ │

└────────────────────┘

(the four engines accelerate one another)

Taken in isolation, none of these four engines is very frightening. People have always formed groups, media has always carried bias, people have always liked their own beliefs, and institutions have always created incentives. What is frightening is when they operate at the same time, reinforcing one another. As identity hardens, we seek out echo chambers more; echo chambers heighten hostility; that hostility pressures institutions to reward confrontation; and the institutions so shaped harden identity again. With each turn of the gear, the division deepens a little more.

4. How Do We Measure Polarization? Gauging the Invisible

The feeling that "we have grown more divided" is vivid, but feeling alone cannot tell us what has changed, or by how much. So researchers have tried, somehow, to translate invisible hostility into numbers. Knowing how they do it also helps you read related news coverage critically.

The Feeling Thermometer

One of the most widely used tools is the "feeling thermometer." Respondents rate a given group from 0 degrees (very cold, negative) to 100 degrees (very warm, positive). The larger the gap between the temperature assigned to one's own camp and to the opposing camp, the deeper the affective polarization. In many societies, this gap has been observed to widen over time.

Social Distance Questions

Another method asks about the distance of everyday relationships. "How would you feel if a supporter of the opposing camp married into your family?" "Would it make you uncomfortable to have such a person as a neighbor or coworker?" When discomfort on such questions grows, it shows that politics has seeped into the domain of private relationships.

Knowing the Limits of Measurement

These measures have limits, too. People sometimes exaggerate their views in surveys, or choose the socially desirable answer. Results can shift depending on how a question is worded. So rather than treating a single figure as absolute truth, we need the caution of trusting more when several measures point in the same direction. That caution is itself a form of critical thinking.

5. Scenes from History: Is Division New?

It is easy to treat polarization as an unprecedented catastrophe unique to our time, but history shows that deep social division is a recurring phenomenon.

Many societies have passed through periods of fierce division—over religion, class, region, and the shape of their own systems—sometimes spilling into violence. And many of those societies came through the division and found, once again, a way to coexist. This does not mean there is no cause for concern; it means polarization is not an unchangeable fate.

Another lesson history offers is that division becomes most dangerous when **the other side is defined not as a "political competitor" but as an "enemy to be eliminated."** In a healthy democracy, the opposing side is someone to defeat at the next election, not something whose very existence must vanish. The moment that line is crossed, the politics of debate degenerates into the politics of survival.

Tellingly, the cases where division was stitched back together share something in common. Reconciliation began not because one side won completely, but when both sides rediscovered a larger identity they could share—as a people, as citizens, as neighbors. We will return to this clue later.

The Arc of Division and Healing

The process by which a division deepens and then heals has stages that recur. Rather than a specific event in one country, the general arc observed across many societies can be sketched like this:

[The general arc of division and reconciliation]

Stage 1 Latent Different values coexist, peacefully adjusted

Stage 2 Ignition A specific event sharpens the partisan line

Stage 3 Rallying Each camp tightens internally; the middle is squeezed

Stage 4 Demonizing The other recast from "competitor" to "enemy"

Stage 5 Gridlock Distrust collapses shared facts and cooperation

Stage 6 Fatigue Everyone feels the cost of prolonged deadlock

Stage 7 Rediscovery A larger shared identity and contact restore the clue

What matters is that this arc is not a one-way street. Some societies leap straight from Stage 4 to Stage 7; others slide back to Stage 2. Whatever stage you are in, there is always room to change direction.

6. Common Myths: Five Misconceptions About Polarization

When we talk about polarization, certain common beliefs come up that, examined closely, run counter to the facts or are far too simple. Checking them is itself good practice for critical thinking.

Myth 1: "People have gone to the extremes on policy"

As we saw, in many societies the distribution of ordinary citizens' policy preferences has not spread to the two ends as much as assumed. What changed more steeply was not policy distance but feeling toward the other side. In other words, we have grown more distant in our "feelings" about each other than in our "thoughts."

Myth 2: "Polarization is one camp's fault"

The most common and most dangerous misconception. Polarization is a phenomenon in which four structural engines interlock, not a conspiracy launched by a single group. The moment we head toward the conclusion "actually, the other side is more of a problem," that diagnosis itself advances polarization by one notch.

Myth 3: "A society without conflict is a healthy society"

A society without conflict may be not a healthy one but a silenced one. The measure of health is not the absence of conflict but the capacity to handle conflict peacefully. The noise of diverse voices colliding and being adjusted is, in fact, a sign that democracy is alive.

Myth 4: "We split because of a lack of information"

More information does not necessarily lead to less hostility. Because of confirmation bias, we sometimes use more information to reinforce our own beliefs. More important than the quantity of information is the attitude we bring to it—above all, the ability to doubt the information on our own side.

Myth 5: "A moderate person is an indifferent person"

Believing strongly and hating strongly are different. A person who deeply supports a value while still respecting the other side as human is not indifferent but participating in the most mature form. Moderation is not the absence of conviction but the balance of holding conviction and respect together.

7. A Pause: A Small Self-Diagnostic

It is worth pausing here to ask yourself, honestly, a few questions. There are no right answers. They are simply a mirror for your own mind.

- Can I describe the opposing camp's position so fairly that someone from that side would say, "Yes, that captures my view exactly"?

- Can I admit the weakest argument on my own side, or do I feel my camp is right in every respect?

- Is my judgment of a given policy based on its content, or on who proposed it?

- When I picture the other camp, do I picture the most reasonable person among them, or the most extreme?

If you found these questions hard to answer, that is nothing to be ashamed of. The human brain works this way by default. What matters is noticing how it works. Noticing, by itself, creates a little distance.

8. The Consequences: What Is at Stake?

What happens when affective polarization deepens? Let us weigh several aspects in a balanced way.

The Erosion of Trust

The first thing to collapse is trust. When you see the other camp as an enemy, you come to doubt even the institutions they run and the facts they produce. As the attitude "whatever their side controls cannot be trusted" spreads, the very ground of shared facts begins to shake. Without common facts, meaningful debate becomes impossible.

What is especially dangerous is when even fact-checking institutions or expert communities begin to be suspected as partisan tools. When reactions like "that statistic was made by their side, so it can't be trusted" become general, we no longer share the same reality. Differing in opinion is the normal state of democracy, but having even "what the facts are" split along partisan lines is a problem of a different order. Debate is possible atop a difference of opinion, but impossible where the sharing of facts has collapsed.

Legislative and Governing Paralysis

In an environment where compromise is seen as betrayal, politicians find it hard to cooperate. Joining hands with the other side, braving the wrath of your own camp's hardliners, can become political suicide. As a result, even urgent problems can stall in gridlock. Paradoxically, the society that fights most fiercely can become the society that solves the least.

There is a subtle trap here. A hardline stance is rewarded by one's own camp in the short term. Supporters tend to like "fighters" and regard "compromisers" as weak. So for an individual politician, confrontation becomes the rational choice, while for society as a whole the result is that nothing gets solved. Everyone behaves rationally for themselves, yet collectively everyone loses—a classic collective-action dilemma. The key to solving it lies not in relying on individual goodwill alone, but in gradually changing rules and culture so that compromise is rewarded.

The Fracturing of Relationships

Polarization affects not only the public square but the dinner table. Political views become a criterion that divides friends and family, and people increasingly associate only with those like themselves.

As real chances to talk with people who think differently shrink, our imagination of them grows more distorted—because we tend to picture the people we never meet in their most extreme form. The absence of contact feeds hostility, and that hostility makes us avoid contact again, in a vicious cycle. This is why the simplest way to break the loop is, paradoxically, just to meet a different person and talk with them directly.

A Balanced View: Is Conflict Always Bad?

One thing must be made clear, though. Not all disagreement is a disease. A healthy democracy is not a system that eliminates conflict but one that handles conflict **peacefully and productively**. The very process by which different values and interests collide and are adjusted is the heart of democracy. The problem is not the fact that opinions differ, but the attitude of seeing people with different opinions as less than human. What we need to reduce is not the diversity of opinion but the intensity of hostility.

9. Drawing Closer Again: Clues for Cooling Down

So what can be done? Polarization is a vast, structural phenomenon that no single person's effort can reverse. But research and experience point in several directions. None is a cure-all, but together they carry weight.

Clue 1: The Contact Hypothesis

Social psychology holds an old idea called the **contact hypothesis**. Systematized by psychologist Gordon Allport, it proposes that, under the right conditions, people from different groups who meet and interact directly will see their prejudice and hostility decline.

The key is "the right conditions." Allport held that, for contact to reduce prejudice, conditions like the following are generally needed:

- Equal status: not a relationship in which one side looks down on the other.

- A common goal: something both want to achieve together.

- Cooperative interaction: meeting within a structure of cooperation, not competition.

- Institutional support: norms or an environment that uphold the encounter amplify the effect.

When these conditions are met, the experience of building or solving something together turns an abstract "them" into a concrete single person. It is far harder to demonize someone whose face you know, with whom you have sweated. Conversely, aimless contact without these conditions can even worsen conflict, so the simple prescription "just get them to meet" should be treated with caution.

Clue 2: Deliberative Democracy

**Deliberative democracy** is an experiment in which randomly selected citizens are given ample information, hear from experts, and engage in deep conversation with people who disagree, before reaching conclusions. It has been tried in various countries in the form of citizens' assemblies and citizens' juries.

Citizens who take part in such forums often report shifting toward more moderate and thoughtful positions than when they started. What is interesting is that this happens not because opinions converge on one side, but because participants directly experience that the other side's position has its own reasons. Given the conditions for good conversation, people are more reasonable than we expect.

Why does this change occur? Everyday political talk is usually short, provocative, and closer to a "performance" aimed at an audience. We hurl clever lines toward our own camp rather than trying to persuade the other side. A deliberative setting, by contrast, has ample time, accurate information, and—above all—a "rule of hearing the other person out to the end." The same people behave differently when the environment changes. This suggests that humans are not inherently rational or irrational beings but ones capable of showing both faces depending on the conditions they are given. If so, what we can design is not human nature but the conditions of conversation.

Clue 3: Media Literacy and Critical Thinking

At the individual level, the most powerful tool is **critical thinking**. This does not mean only the ability to doubt. It is closer to the ability to doubt yourself.

Concretely, you can start with small habits like these:

- When you meet content that makes anger surge up, pause for a breath before hitting the share button and ask, "Who is showing me this, and why?"

- The more intense the claim, the more you trace it back to the original source. Quotes are often cut from their context.

- For a single event, deliberately read one more piece of coverage from a perspective different from yours.

- When you see a statistic or a graph, check whether the baseline and the comparison were chosen fairly.

- Above all, scrutinize most strictly the information that tells you what you "want to hear."

We usually pick apart the other side's claims while readily believing our own. The real difficulty of critical thinking lies precisely in reversing this balance. It is easy to doubt others, hard to doubt yourself. Yet that harder direction is the most personal power there is for slowing polarization.

Clue 4: Recovering a Larger Identity

Let us return to the clue we saw in history. Societies that stitched division back together rediscovered a larger identity both sides could share. Beyond "our side versus your side," they redrew a wider circle: "people living in the same society."

This is not a call to erase difference. It is a call to remember the larger common roof under which differences remain, without those differences growing so large that they deny one another's humanity. The simple fact that the person who opposes you politically is still your neighbor, walking the same streets, worrying about the same future.

Psychology calls this "recategorization." It means shifting, in the mind, the boundary of "us versus them" one step further out, to make a larger "us" that embraces both sides. For example, even if parents in the same neighborhood are politically divided, they can be on the same side before the common goal of "a safe route for the children to walk to school." The scene of people forgetting their camps to help one another when disaster strikes works on the same principle. The moment a larger common task arises, the small partisan lines briefly fade. Deliberately creating such moments more often is itself a society-level strategy for cooling down.

[Four clues for cooling down]

Individual level Societal level

──────────────── ──────────────

Critical thinking ←──→ Deliberative forums

Larger identity ←──→ Designed contact

Core: reduce hostility, but keep diversity

10. Modern Implications: New Variables of the Digital Age

Most of the mechanisms we have examined are old in human history. Group instinct, confirmation bias, and the incentives of institutions are not new discoveries. So is there really something new about polarization in our time? Let us touch on a few variables of the digital age.

Speed and Scale

In the past, a rumor took days to make its way around a village. Now a provocative claim reaches millions in minutes. Anger is amplified before it has a chance to cool, and corrections never catch up with the original claim. The change in speed and scale did not create new "engines" of polarization, but it dramatically raised the rotation speed of the existing ones.

Anonymity and Distance

The person on the other side of the screen has no face. Words we could never bring ourselves to say to someone in front of us, we throw easily at an anonymous opponent. Physical distance and anonymity weaken the circuits of empathy and flatten the other into an abstract "representative of a camp." It amounts to making the very opposite of the "face-to-face relationship" stressed by the contact hypothesis into the default.

Anger, Measured and Rewarded

Many of today's platforms rate the value of content by the volume of reactions. And anger is one of the best-measured and best-rewarded emotions, because fierce anger generates more clicks and shares than calm agreement. When anger becomes a kind of currency like this, people are nudged, without realizing it, into producing ever more anger.

Yet Tools Cut Both Ways

We must not forget, though, that the same technology can be used in the opposite direction. People far apart can cooperate, closed information can be opened up, and small voices can connect into a great force. Technology itself is not the enemy. The question is what the technology is designed and used to reward. And so the seat of hope is right there, too—because design and use are, in the end, things people can change.

11. The Ethics of Balance: What This Essay Does Not Do

Before closing, I want to be clear about what this essay deliberately did not do.

It did not judge which party or ideology should bear more responsibility for polarization. That is a deliberate choice. The moment an essay about polarization slides into "but actually, the other side is more to blame," that essay becomes a component of polarization itself.

Nor does this essay argue for a relativism in which all views are equally valid. Some claims are better supported by evidence than others; some policies are more effective than others. The goal of critical thinking is not to abandon the distinction between right and wrong, but to **draw that distinction based on evidence rather than the banner of a camp**.

The core is this: you can strongly oppose someone without hating them. You can argue about opinions to the end while still respecting the person. The capacity to do both at once is, in a divided age, the rarest and most necessary skill there is.

12. A Short Quiz: Make the Concepts Your Own

A small quiz to consolidate what you have read. Recall your answer, then compare it with the explanation just below.

**Question 1.** Between "I oppose that policy" and "I dislike the people who support that policy," which one corresponds to affective polarization?

Explanation: The latter. Affective polarization refers not to a difference in policy position but to emotional hostility toward the opposing camp. The former is closer to issue polarization.

**Question 2.** What was the key point of Tajfel's minimal group experiments?

Explanation: That even in groups divided by meaningless criteria, with no real stakes or history at all, people immediately favored their in-group. It shows that bias kicks in the moment a line of "us and them" is drawn.

**Question 3.** Is it accurate to say a recommendation algorithm has an "intention" to divide society?

Explanation: Not accurate. An algorithm's goal is usually to maximize time on the platform, and a tendency to surface hostility-provoking content arises incidentally in that process. It is more accurate to see it as a problem of structure, not intention.

**Question 4.** In the contact hypothesis, why is "merely crossing paths" not enough?

Explanation: Because the prejudice-reducing effect appears strongly when the conditions of equal status, a common goal, and cooperative interaction are met. Contact without those conditions can even worsen conflict.

**Question 5.** Why did this essay not judge "which camp is more to blame"?

Explanation: Because the moment an essay about polarization slides into a blame game between camps, that essay itself becomes a component of polarization. Keeping the diagnosis neutral is the attitude consistent with the subject.

Closing: Back to the Table

Let us return to the holiday table where we began.

When the uncle's voice rose and the air hardened, there were, in fact, two choices in that moment. One was to retreat more deeply into one's own camp, silently regarding the other as pitiful. The other was to pause for a beat and ask: "What led you to think that? I'm curious about where that feeling comes from."

The second path is awkward and may not always work. But that one question briefly breaks the circuit of hostility, because it returns the other person from "an enemy to overcome" to "a person to understand."

Polarization is a vast structure, but that structure is ultimately made of countless small moments. The moment you doubt the screen once more, the moment you deliberately seek out the other side's most reasonable argument, the moment you ask instead of hate. These small choices we make every day shift the temperature of the whole society, ever so slightly.

Why are we drifting further apart? The most honest answer is that it is not the plot of a single villain but a vast gear we all turn together. If so, slowing that gear, too, rests a little in all of our hands.

Questions to Sit With

- Can you describe the political position you most strongly oppose so fairly that someone who holds it would be satisfied?

- The political content that most enraged you recently—who made it, and with what intention?

- If you were to restart a conversation with a politically different friend or relative, what would you want your first question to be?

- What is a "larger common goal" that you could pursue together even with someone politically opposed to you?

- When have you judged by the "label" rather than the "content"? What led that judgment at the time?

References

- Allport, G. W. (1954). _The Nature of Prejudice_. Addison-Wesley.

- Tajfel, H. (1970). "Experiments in Intergroup Discrimination." _Scientific American_.

- Iyengar, S., Lelkes, Y., Levendusky, M., Malhotra, N., & Westwood, S. J. (2019). "The Origins and Consequences of Affective Polarization in the United States." _Annual Review of Political Science_.

- "Political polarization." _Encyclopaedia Britannica_. https://www.britannica.com/topic/political-polarization

- "Confirmation bias." _Encyclopaedia Britannica_. https://www.britannica.com/science/confirmation-bias

- Levitsky, S., & Ziblatt, D. (2018). _How Democracies Die_. Crown.

- Mason, L. (2018). _Uncivil Agreement: How Politics Became Our Identity_. University of Chicago Press.

- "Social identity theory." _Stanford Encyclopedia of Philosophy_ related entries. https://plato.stanford.edu/

- "Cognitive bias." _Encyclopaedia Britannica_. https://www.britannica.com/science/cognitive-bias