Today's article comes from the Frontiers in Psychology journal. The authors are Liu et al., from Shenzhen University, in China. In this paper they're exploring whether or not digital-hoarding impacts cognitive functioning.
DOI: 10.3389/fpsyg.2024.1518860
On December 8th, 2022, the Google Chrome team announced "Memory Saver": the browser's new ability to free up RAM from unused tabs, so that it could be used in the tabs you've interacted with more recently. For most people, this was probably a non-event. For people like me, it was huge. A breath of fresh air. Why? Because I have, let's say....an unusually high number of tabs open at any time. Hundreds. And Memory Saver allows me to push that number ever higher. A page I find interesting? That's an open tab. A page I might need to come back to later? That's an open tab. A topic I'm researching? A collage of interrelated tabs.
Do I ever close them? Clean them up? That's like asking if I would ever throw away my keys. Why would I do that?
Is this a problem? Do I have a problem?. Maybe. But if so, Chrome is certainly an enabler.
It turns out, they have a term for this. It's called "digital hoarding", and it's exactly what it sounds like. The persistent accumulation of digital content, coupled with an unwillingness to delete it. We're not talking about the occasional saved article, or folder of screenshots you'll never look at again, no. We're talking about needing to uninstall apps from your phone because you've got too much other stuff on it. We're talking about getting trapped into an icloud backup subscription or a dropbox membership that you'll never ever be able to cancel.
Other studies have found that somewhere between 3% and 6% of the general population engages in this kind of pathological digital hoarding. But that number jumps to over 21% among young people. More than one in five are compulsively accumulating digital stuff they'll never ever use or even ever see again.
The question is: is this a benign idiosyncrasy? Or is this behavior possibly causing real harm? That's what the authors of today's paper are trying to figure out. In it, they constructed a moderated mediation model to explore whether digital hoarding impacts cognitive functioning. On today's episode, we'll walk through how they measured hoarding behavior, how they tested the mediating role of fatigue, and how they evaluated mindfulness as a moderator of both the direct and indirect pathways. We'll dig into their statistical approach, examine the correlation patterns they found, and look at what the moderated mediation results actually tell us about who's most vulnerable to negative consequences of this behavior.
First, we need to review a couple key terms that we'll be using a lot today: mediating, and moderating.
A mediator explains how or why one variable affects another. It's the middle link in a causal chain. Imagine you're studying why stress leads to poor concentration. You might find that stress increases fatigue, and fatigue, in turn, reduces concentration. In that case, fatigue is the mediator, it carries part of the effect from stress to concentration. The relationship is indirect, so if you remove fatigue from the equation, the connection between stress and concentration weakens or even disappears. You've taken away the mechanism that transfers the effect.
A moderator affects the strength or direction of a relationship. It answers the question, "When or for whom is this effect stronger or weaker?" So for example: social support can moderate the link between stress and depression. That is to say: stress may cause more depression in people with low social support than in those with strong support networks. Similarly, sleep quality might moderate how caffeine affects alertness: people who are already well rested don't get as much of a boost as those who are sleep deprived. To put another it way: moderators don't explain a process, they change its intensity, directionality, or slope.
When you combine both concepts, you get something called "moderated mediation": a model that asks whether the size of an indirect effect depends on another variable. In other words, does the mechanism itself operate differently across contexts or individuals? Suppose that the link between stress and fatigue depends on physical fitness: people who are fitter don't tire as easily under stress. In that case, fitness moderates the first half of the mediation pathway. Or maybe the fatigue-to-concentration link depends on caffeine intake, which would moderate the second half. In either case, the mediation still exists, but its strength varies depending on the moderator. Moderated mediation.
That is what the authors tested here. They proposed (or hypothesized) two things:
To test this, they first needed to figure out how to measure digital hoarding accurately. They ended up using a revised version of the Digital Behaviors Questionnaire. It contains seven items split into two dimensions. The first dimension is "accumulation," which captures the behavioral tendency to continuously save digital files. The second dimension is "difficulty in discarding," which reflects the emotional and practical challenges of deleting digital content. They gathered together about 800 college students, and had them each rate every item on a five-point scale (from strongly disagree to strongly agree). A participant's total score represents their overall digital hoarding tendency (higher scores indicating more severe behavior).
For fatigue, they used a different device: the Fatigue Assessment Scale, a ten-item measure that asks participants to rate statements like "I feel somewhat exhausted," "I find it difficult to start tasks," and "My thoughts are sometimes unclear." Responses range from "never" to "always", and the average across all items represents the participant's overall fatigue level. The higher the score, the greater the perceived fatigue.
Cognitive failures were measured using the Cognitive Failure Questionnaire. This one's an eighteen-item instrument covering three domains. Attention failures, memory failures, and action execution failures. Participants rate how often they experience each type of failure on a five-point scale, and the total score represents overall cognitive failure frequency.
Finally, mindfulness was assessed using the Child and Adolescent Mindfulness Measure: ten-items originally developed for younger populations but validated for use with college students. All these items are reverse-scored, meaning they describe states of "mindlessness" rather than mindfulness. These are phrases like "I have trouble focusing on one thing" and "I often think about the past rather than the present." Participants rate each item on a scale from 0 to 4, representing "never" to "always". Reverse-scoring inverts the values, so higher average scores end up indicating higher levels of mindfulness, not the opposite.
The authors tabulated the results then checked for common method bias, using a technique called Harman's single-factor test. This is important because all their data came from self-reported surveys completed at the same time. This has the potential to artificially inflate correlations between variables. The single-factor test works by conducting an exploratory factor analysis and seeing how much variance is captured by the first factor. If one factor accounts for more than 40% of the variance, that's a red flag for this kind of bias. In this case, the first factor accounted for only about 31% of the variance, suggesting common method bias was not a major concern.
They also verified that their data met the assumptions for regression analysis. It passed: the distribution shapes for all the variables fell within acceptable ranges and created reasonably normal distributions. They also checked that data points were independent of each other and that there wasn't excessive correlation between predictor variables that would make the model unstable.
Then it was time to crunch the numbers. Let's see what they found.
Correlation analysis revealed several patterns. Digital hoarding showed moderate positive correlations with both fatigue and cognitive failures. Fatigue showed an even stronger positive correlation with cognitive failures. Meanwhile, mindfulness was negatively correlated with all three variables: digital hoarding, fatigue, and cognitive failures. All of these correlations were statistically significant.
To test the mediation model, they used a technique called bootstrapping. This involves repeatedly resampling the data thousands of times to generate reliable confidence intervals for the effects. The results showed that digital hoarding significantly predicted cognitive failures. Even after including fatigue as a mediator, the direct effect of digital hoarding on cognitive failures remained significant, indicating partial rather than complete mediation.
The key pathway worked exactly as expected. Digital hoarding significantly predicted fatigue, and fatigue significantly predicted cognitive failures. The confidence intervals for both the direct and indirect effects excluded zero, confirming that both pathways were statistically reliable. The direct effect accounted for about 58% of the total effect, while the indirect effect through fatigue accounted for about 42%. This means that digital hoarding influences cognitive failures through two routes: a direct path and an indirect path mediated by fatigue.
So what does any of this actually mean? Well, when you engage in digital hoarding, constantly saving and accumulating content, this study shows that you're depleting your cognitive resources. Every decision about whether to save something, every moment spent scrolling through saved items you'll never actually use, every pang of anxiety about your overflowing digital collections, all of this drains mental energy. That depletion manifests as fatigue, both mental and physical. And that fatigue then impairs your ability to perform everyday cognitive tasks effectively.
But the story doesn't end there. Remember, the authors hypothesized that mindfulness would moderate these relationships, meaning the effects should be different for people with different levels of mindfulness. To test this, they used a statistical model that allows for moderation of both the direct path from digital hoarding to cognitive failures and the first stage of the mediation path from digital hoarding to fatigue.
The results confirmed their hypothesis. The interaction between digital hoarding and mindfulness significantly predicted both cognitive failures and fatigue. These negative relationships indicate that as mindfulness increases, the unwanted effects of digital hoarding decrease. In other words, mindfulness acts as a buffer, protecting people from the worst effects of their digital hoarding behavior.
The practical implications are pretty straightforward. In an ideal world, students wouldn't be hoarding digitally. But for many of us, that's just the reality. Unchecked, this has significant negative consequences. But, cultivating mindfulness (whether that be through meditation, or breathing exercises, or even mindfulness-based apps) might have the potential to help us all manage the cognitive toll of our digital hoarding.
Problem solved? Ehhh...no. Problem moderated.