What makes something real?

What is the color red?

What counts as a mountain versus a hill? What is a president, and what powers does a president have?

According to Lisa Feldman Barrett, PhD, a University Distinguished Professor of Psychology at Northeastern University, the answers have something important in common: They depend, at least in part, on people collectively assigning meaning to physical signals in the world.

“What you do, what you don’t do, what you say, what you don’t say — your daily actions help to constitute reality, help to manifest reality,” Barrett says.

A different way to think about reality

It’s part of a theory known as “relational realism,” which holds that many features we assume are objective aspects of reality actually emerge from the relationships between what exists in the world and what exists within us.

Take color. Red isn’t simply a property of an object. It’s a property of the relationship between the wavelengths of light that hit your retina and the signals processed in your brain.

How does your brain know to interpret those signals as red? You had to learn what those patterns meant, which means, at some point, other people helped teach you.

How your Perception Box is built

Barrett refers to this process of learning to assign meaning to physical signals as “cultural inheritance.”

“Cultural inheritance is how other people, by virtue of their actions and their words, wire your brain with the remembered past that you now use to create the relational present,” she says. “Cultural inheritance is a form of passing knowledge from one generation to another.”

In other words, much of the knowledge and meaning we use to understand reality isn’t simply out there waiting for us to discover it. It’s also passed down by those around us, becoming part of our Perception Box: the invisible mental container of accumulated experiences and concepts we use to make sense of the world.

The reality we create together

When groups of people collectively assign meaning to something that doesn’t intrinsically carry that meaning on its own, they create what’s referred to as “social reality.” It depends on some degree of shared understanding or consensus.

Consider a burgundy chair. The wavelengths of light reaching your eyes don’t come labeled “burgundy.” Rather, your identification of that color depends on patterns you learned in the past and now use to interpret the signals reaching your brain.

“So, in all cases, the signals outside our heads are given meaning by their relation to the signals inside our heads by consensus — by collective agreement — which means that even something like the existence of color is a form of social reality,” Barrett explains.

How collective agreement creates — or erases — value

Money is a classic example of social reality.

“Every time you trade little pieces of paper for something that you can eat or that you can use, you are not just agreeing to the existence of money, you are manifesting the existence of money,” Barrett says. “And the more people who agree, the more solidified the value becomes.”

Thus, if enough people were to withdraw their shared agreement that those pieces of paper could be exchanged for goods, that form of money would lose the meaning that gives it economic power.

Barrett points to the 2008 mortgage crisis as an example of what happens when collective judgments about value shift dramatically, describing it as a moment “where a group of guys in suits withdrew their consent that mortgages had a certain value.”

In other words, social realities can crumble, with real consequences, Barrett says: “The world was plunged into an economic crisis as a result.”

Reality can bend, but only so far

While reality is perspective-dependent and flexible, it’s not infinitely flexible.

“You can’t just make up any bullshit, get consensus for it, and then it counts as true,” she says. “We could get a bunch of people to agree that [crushed] glass is food, but that would not make it true.”

Barrett explains that’s because shared meaning is never the only signal that matters; in the example above, there are biological constraints helping to determine what counts as food. “The patterns that emerge from those signals also matter a great deal. They’re crucial.”

In the end, we are all contributing to reality by what we do and don’t do. Whether we vote or don’t vote, follow a social influencer or don’t, or choose to eat one thing instead of another — all of those decisions manifest the reality we have to deal with.

“You have more power for which signal patterns count as reality and which ones do not,” Barrett says.

We interviewed Lisa Feldman Barrett for Relational Realism, a Big Think interview series created in partnership with Unlikely Collaborators. As a creative non-profit organization, they’re on a mission to help people challenge their perceptions and expand their thinking. Often that growth can start with just a single unlikely question that makes you rethink your convictions and adjust your vantage point. Watch the third episode above, and visit Perception Box to see more in this series.

This video is featured on Big Think.