Why We Talk to Ourselves: The Science of Your Internal Monologue

Some of us chatter to ourselves all day long while others’ inner lives take the form of pictures or, like Einstein, abstract visual concepts. But as mindfulness urges us to pay more attention, it’s worth asking: What can our interior life teach us?

Illustration by Edmon de Haro

“Know thyself,” was the advice inscribed on the Temple of Apollo at Delphi. The Tao Te Ching insisted that knowing others is intelligence, while knowing oneself is true wisdom. “To thine own self be true,” Shakespeare urged.

Pithy advice. Good advice. Advice that spans centuries and civilizations. But…how exactly do we do that? University of Nevada psychology professor Russell Hurlburt thought a good start was paying attention to the thoughts in our head. Not the eureka! thoughts, necessarily, but the mundane. The “What should I make for dinner tonight?” thoughts. The “That’s a pretty shade of blue” thoughts. The self-reproaching “That was a dumb thing to say” thoughts or the self-encouraging “You can do this” thoughts. The thoughts that, in meditation, we’re taught to label as “thinking.” The thoughts that we barely notice, or that we feel dogged by. The thoughts that, as psychologist and neuroscientist Ethan Kross writes in his book Chatter: The Voice in Our Head, Why It Matters, and How to Harness It, allow us “to hold information in our minds, reflect on our decisions, control our emotions, simulate alternative futures, reminisce about the past, keep track of our goals, and continually update the personal narratives that undergird our sense of who we are.” In other words, to “know thyself,” we have to first pay attention to the voices in our head.

Meet Your Internal Monologue

But first, let’s get clear. While lots of us do, in fact, have voices in our head, many of us don’t. What some have instead are images, symbols, sensations, or, if we’re like Einstein, abstract concepts. Consider too that some deaf people experience inner “speech” even if they’ve never heard a human voice.

Russell Hurlburt, arguably the grandfather of “inner experience” research, ultimately came up with five categories: inner speaking (voice), inner seeing (pictures/images), feelings (happy, sad), sensory awareness (carpet beneath our feet), and unsymbolized thinking (which basically includes awareness of a thought but without words or pictures).

Nobody has managed to quantify how many of us experience this inner speech, but we do know that, among those that report they do, an estimated quarter of our waking lives are spent talking to ourselves, says Hélène Loevenbruck, a researcher in linguistics and neuroscience at the Laboratoire de Psychologie et Neuro-Cognition, Université Grenoble Alpes in France. Loevenbruck prefers the term endophasia: endo = inside, phasia = speech. “It’s just language inside us,” she explains, “and it’s neutral as to whether it’s a dialogue or a monologue, whether it’s speech or sign language or whatever.”

Our brains, however, may tell the difference. Thanks to fMRI, we now know that the brains of people who are engaged in inner speech show activation in the left inferior frontal cortex, which is one of the crucial regions devoted to speech. Instead, the brains of those whose thoughts are made up of images, or abstract feelings, might reveal activation in the semantic regions, which interpret meaning from what our senses take in—including the middle temporal cortex and possibly visual cortex, says Loevenbruck.

Whatever we call it and however we experience it reflects the same thing: an interior life that, when examined, can help us know ourselves better.

What Was I Thinking

It was roughly 50 years ago that Russell Hurlburt undertook an experiment that involved giving people a notebook and a beeper that would go off randomly. When participants heard the beep, they were instructed to stop what they were doing and jot down in the notebook what their inner experience was at that moment. Hurlburt was resurrecting an aspect of psychology that had fallen out of favor—that of quantifying our conscious experience.

Hurlburt estimates he’s included thousands of people in his studies, which relied on Descriptive Experience Sampling (DES). DES uses an open-ended questionnaire to try to get people to accurately describe what was happening in their minds when the beeper went off.

Our presuppositions about what we’re thinking get in the way of truly knowing our minds.

Easier said than done, he discovered. “That seems like a very straightforward instruction,” he says. But when people would report back, Hurlburt got information about context and what he calls “presupposition.” Presupposition, he says, means that “People drew up their own beliefs about the way the world was and what their inner experience was, and then they ended up telling me about their beliefs rather than what their inner experience was about.” For instance, he said, subjects often believe they’re talking to themselves when they’re actually experiencing a sensation. He uses the example of a subject who might report that, when the beep went off, she was saying to herself, “What a delicious wine this is.” When pressed, however, the subject ultimately reports that she wasn’t so much talking to herself as experiencing the taste. Reflecting their presuppositions instead of their inner experiences proved a high hurdle for most study participants to clear. Our presuppositions about what we’re thinking—more than what we’re actually thinking or experiencing—get in the way of truly knowing our minds, Hurlburt says.

There was one notable exception, however. “Adept meditators didn’t have that problem,” Hurlburt says. “They could tell you what was going on.” They were particularly attuned to one of Hurlburt’s five identified categories of inner thoughts: sensory awareness. For example, if they saw a  gold door handle, they noticed its goldness rather than what the handle is  used for. “The adept meditators had a lot of sensory awareness,” he says. “So  much of mindfulness training is basically about paying attention to sensory  aspects. Adept meditators have done quite a bit of that.” 

Don’t Believe Everything You Hear

But paying attention to our inner life is just one part of knowing ourselves. We then need to learn how to put that awareness to