The Psychology of Polarization

As part of the Kettering Foundation’s ongoing research, our staff and allied organizations gather for monthly Dayton Days research sessions to reflect on the ideas guiding our work and to share new insights. Conceptual thinkers from outside the foundation join us to talk about their work and provoke our thinking.

In December 2022, we invited Mylien Duong, senior director of research of the Constructive Dialogue Institute (CDI), to join us. CDI uses the psychological processes that influence decision-making to create tools that can help students and professionals have conversations across differences. We asked, What roles do unconscious mental processes play in how we understand and respond to shared problems, and how can these tools help reduce the levels of political mistrust, division, and animosity?

When the image of “the dress” went viral in 2015, I had just started dating my now-husband. A friend of ours showed us the viral photograph over dinner and asked us what color the dress was. I saw blue and black. My husband saw white and gold. It was only the honeymoon politeness that kept me from asking him, “Are you out of your mind?” Even after the viral debate, knowing that a large portion of the population sees gold and white, and even knowing the neuroscience behind the visual illusion, to this day, I can’t help but feel just a tiny bit vindicated that the actual dress was determined to be blue and black.

If we can feel righteous over something as inconsequential as a color of a dress, do we even stand a chance when it comes to moral disagreements about how we treat the earth, vaccines as necessary public health measures, or if it’s okay to decide whether a fetus lives or dies?

Jon Haidt, cofounder of CDI, had spent much of his career trying to answer such questions. In 2004, he and colleagues proposed the moral foundations theory. He likened our morality to taste buds. We all have the same taste buds on our tongues (salty, sweet, sour, bitter, and savory), yet we all have different taste preferences. My husband is a chocolate fiend; I would much rather indulge in a bag of potato chips. And despite the universality of our taste buds, world cuisines are incredibly diverse.

Moral foundations theory states that humans begin with the same six moral foundations:

1. Care: The Care foundation serves as the basis for caring for others and trying to prevent harm. This underlies the values of kindness and compassion.

2. Fairness: We all want to be treated fairly, and we dislike when people cheat—even when we’re not the ones who are directly affected by the cheater’s actions. This foundation underlies the values of justice, equality, and reciprocity. It’s also connected to the values of honesty and integrity. Those on the political right and left tend to interpret fairness differently. Those on the political right tend to think about fairness in terms of proportionality (people should benefit in proportion to which they contributed). Those on the political left tend to think about fairness in terms of equality (people should have equal outcomes). This underlies the tension between equality and equity.

3. Liberty: The Liberty foundation underlies our desire for autonomy—the freedom to make our own decisions. This serves as the basis for the ideal of individual freedom as well as the desire to eliminate oppression. Those on the political left and political right tend to care a great deal about the liberty foundation. However, they tend to apply it differently. Those on the political left tend to rely on the liberty foundation to advocate for vulnerable populations who they believe are oppressed by the dominant population. Those on the political right tend to rely on the liberty foundation in their desire for freedom from government regulation.

4. Loyalty: This foundation underlies the drive to be loyal to groups that we’re a part of—for instance, our family, company, neighborhood, religious community, sports team, etc. The Loyalty foundation also forms the basis of values like patriotism, being a team player, and self-sacrifice for the sake of the group.

5. Authority: The Authority foundation underlies the value of respecting traditions, laws, leaders, elders, and other forms of authority that you consider legitimate.

6. Sanctity: The Sanctity foundation underlies the notion that certain things are “pure” or sacred, and that they should be protected or treated with reverence. This can manifest in treating objects and beliefs as sacred. It can also underlie the notion of treating the human body like a temple that must not be desecrated. The Sanctity foundation underlies ideas related to religion, or the protection of symbols that people view as sacred (e.g., flags and monuments). It can also underlie the desire to protect the environment.

Moral foundations theory further states that, although we all share these same foundations, we draw on them in different ways and to different degrees to form our specific moral worldviews. Further, research shows that people on the political left and right tend to build moral worldviews that rely primarily on different moral foundations. This pattern has been found across hundreds of thousands of people, and it can be seen in political divisions across countries all over the world.

As the graph below illustrates:

  • People on the political left tend to rely mostly on the Care, Fairness, and Liberty foundations.
  • People on the political right also rely on the Care and Fairness foundations, but to a lesser extent. But they rely a lot on Liberty, as well as Loyalty, Authority, and Sanctity.

I believe that moral foundations theory has been so influential because it gives us an alternative to the binary us-versus-them thinking that predominates so much of our media. It’s given me, and many other people, hope. Hope that there’s more to the story than “the other side is full of idiots.” Hope that even among our most vociferous arguments, we can find something that we share. And hope that that we can impart to the next generation not a specific set of values or opinions, but the ability to look at information and discern for themselves what they think, the skills to turn to their peers and exchange their opinions in a genuine and respectful way, and to use both their commonalities and their differences to build a better world together.