Why Do Some Shows or Books Stay with Us for Weeks or Longer?

Sometimes you finish a TV show or book, and within a week, you can barely remember anything that happened in it. But sometimes it stays with you—it lingers—intruding into your everyday thoughts weeks later. What's responsible for the difference?

Previously, I wrote about the negative impact that binge-watching can have on enjoyment and forming lasting memories of TV shows. A recent study, however, suggests that another factor might play a role in the lingering influence of stories: how deeply you process the story.

The Levels-of-Processing Effect

This idea isn't a new one. It's based on a classic finding from cognitive psychology, originally demonstrated by Fergus Craik and Endel Tulving. In their experiments, subjects were shown lists of words and asked to identify different features about them, like whether they were printed in capital letters or not (shallow processing) or whether they fit grammatically into a sentence or not (deep processing). Everyone then got a surprise memory test: they had to recall as many of the words they had just seen as possible.

Although everyone had seen exactly the same words, those that had to process them more "deeply" recalled more of the words, on average, than those that processed them more superficially.

But does this effect generalize to stories?

What the Latest Study Found

That was the question posed by Buddhika Bellana, Abhijit Mahabal, and Christopher Honey, in their recent study, which is currently posted as a preprint and is not yet peer-reviewed. In one of their experiments, 240 online subjects were split into three groups. They all read a version of Raymond Carver’s short story "So Much Water So Close to Home," but in different orders. One group read the story in the normal (intact) order, one group read the story with the sentences in a randomly scrambled order, and one group read the words in a randomly scrambled order.

The main way the researchers tested whether the story had influenced subjects' thinking was with a free-association task—the sort of task where you are given a word like "dog" and you have to produce the first word that comes to mind.

Subjects did this task both before and after reading the story, so researchers could see whether the story caused the subjects to produce certain words more. That's exactly what they found. As the figure below shows, those who read the intact story were more likely to produce the words "river," "murder," "dead," and "funeral" after reading the story, suggesting that these concepts (which are related to the story's theme) were more accessible to them. More importantly, subjects in the sentence-scrambled and word-scrambled conditions were less likely to produce these words, suggesting that they had not processed the story as deeply as those who had read the story as it was originally written.

Difference in free-association probabilities after reading the story and before.

Source: From Bellana et al.

What Causes Lingering?

To better understand the cause of these lingering influences, the researchers asked subjects to answer a questionnaire called the Narrative Transportation Scale, meant to measure how deeply they were thinking about the story and its themes. The scale has questions like "While I was reading the text, I could easily picture the events in it taking place." The scores ranged from 0 to 1, with 1 being the highest. The mean score for the intact group was 0.64, which was statistically significantly greater than the mean scores for the sentence-scrambled group (mean of 0.52) and for the word-scrambled group (mean of 0.41).

Ten minutes after the end of the experiment, subjects explicitly rated how much the story continued to linger in their minds on a 1 to 7 scale. As the figure below shows, across all three conditions, their narrative transportation scores predicted their lingering ratings reasonably well. This again supports the theory that depth of processing is responsible for the lingering effect.

Transportation scores vs. lingering ratings with best-fit lines.

Source: From Bellana et al.

What Does This Mean?

If this study's results hold up, they have clear implications for how you might go about creating more lingering feelings from the books and shows you consume if that's what you're after. Decades of cognitive psychology research have shown that "deep" processing requires paying attention, making intentional connections between what you're learning and what you already know, and asking yourself questions about it.

There's nothing wrong with watching a TV show while folding laundry or scrolling through Instagram, but it's not likely to produce the deep processing necessary to generate an impression that lingers for weeks.