By Lina Irawan 
The scene unfolded with the dramatic flourish of a low-budget comedy skit, yet it was undeniably real. My wife’s eyes widened, her jaw slightly agape, as I, with the zeal of an Olympic medalist, tore open a FedEx package and hoisted its contents aloft. The delivery driver hadn’t even had time to reverse his truck out of our driveway before I was celebrating my latest acquisition: a Speedo adorned with dinosaur tear-away trunks. The absurdity of the moment hung in the air, thick with confusion, as my wife finally managed to articulate her bewilderment: “Why on earth did you buy a Speedo… with dinosaur tear-away trunks?” The question echoed the silent query forming in my own mind.
Honestly, at that precise moment, I couldn’t recall the specific impetus for such a peculiar purchase. Was it an impulse buy fueled by a fleeting vision of a social media skit, perhaps a desperate attempt to elicit a laugh from her? Or was I merely another "victim" of the digital age, a casualty of a perfectly timed online advertisement that targeted my subconscious at its most vulnerable? This incident, bizarre as it was, served as a stark, personal illustration of a phenomenon I, Matthew Pittman, an associate professor of advertising and public relations at the University of Tennessee, have dedicated years to studying: how social media profoundly influences consumer behavior, often leading us to make purchases we can barely explain.
The pervasive nature of social media means that even a brief 30-second scroll through platforms like Instagram can induce a subtle yet significant shift in our cognitive state. Our brains, bombarded by a relentless stream of diverse content—from friends’ vacation photos and celebrity updates to news headlines and, crucially, advertisements—become measurably more fatigued. This state of mental fog, or "cognitive load," renders us more susceptible to certain types of advertising, particularly those that offer clear, explicit directives rather than inviting nuanced consideration. In such a state, an ad confidently proclaiming, "The facts make it clear, we’re the best!" often resonates more powerfully than one that asks us to "decide for yourself."
My recent research, conducted alongside fellow scholars Stan Li and Bixuan Sun, delves into this very mechanism, underscoring how the mental taxation of processing information fundamentally alters how individuals respond to brand claims. This isn’t merely about superficial engagement; it’s about a deeper, often unconscious, shift in perceived credibility.
Explicit Versus Implicit Pitches: A Deeper Dive
To explore this dynamic, we designed and executed three distinct experiments, each focusing on how people process online advertisements for eco-friendly products. The choice of sustainable products was deliberate; their benefits are often intangible ("50% lower emissions," "ethically sourced") and require a degree of trust and conscious evaluation, making them ideal for testing the impact of cognitive load on credibility perception.
In each study, participants were divided into two groups. Half were subjected to a 30-second scrolling session on Instagram—a common, almost reflexive daily activity for a significant portion of the global population, with half of all U.S. adults engaging with social media daily. This brief exposure was sufficient to induce a measurable level of cognitive load. The other half served as a control group, not engaging in the scrolling activity before viewing the ads. Both groups then viewed an Instagram post from a sustainable brand, with the product varying across the three studies: laundry detergent sheets from Tru Earth, an eco-friendly phone case from Pela Case, and a reusable water bottle from Klean Kanteen. Each ad presented several factual claims about the product’s environmental benefits.
The critical variable we manipulated was the concluding line of the advertisement’s caption. One version presented an implicit conclusion, encouraging independent thought: “Who makes the best, most sustainable detergent? Here are the facts, now decide for yourself.” The alternative presented an explicit conclusion, offering a direct recommendation: “Who makes the best, most sustainable detergent? The facts make it clear – it’s TruEarth!!”
The results across all three studies revealed a remarkably consistent pattern, illuminating the subtle yet powerful impact of cognitive load. Under normal conditions, when participants were not experiencing cognitive load, they overwhelmingly preferred the ads with implicit conclusions. This indicates a natural human inclination towards autonomy and the desire to form one’s own opinions, to feel like a rational, discerning consumer rather than being dictated to. This preference aligns with established theories in psychology and marketing that suggest people value agency and tend to resist overt persuasion when their cognitive resources are ample.
However, the dynamic flipped dramatically when cognitive load was introduced through the simple act of scrolling on Instagram. In this mentally fatigued state, participants consistently preferred the ads that explicitly told them to buy the featured product because it was “the best.” This shift is not a conscious admission of being easily swayed; rather, our research found that credibility was the underlying mechanism. When consumers were under cognitive load and preferred the explicit conclusions, it wasn’t because they consciously recognized or admitted to being impressionable. Instead, the clear, bold, and assertive nature of these claims unconsciously boosted the perceived credibility of the brand. In a state of mental fatigue, directness is interpreted as confidence and trustworthiness, a welcome relief from the effort required to process complex information and draw personal conclusions.
This phenomenon mirrors human social interactions. In everyday life, an overly assertive or "bossy" individual might be perceived as arrogant or annoying. Yet, in times of stress, crisis, or mental exhaustion, that same assertiveness can be reassuring. A confident leader who clearly states the path forward can instill a sense of security when individuals are too overwhelmed to analyze options themselves. The advertising landscape on social media capitalizes on this inherent human response to stress.
Sustainability claims present a unique challenge for advertisers. Unlike a coffee’s flavor or a shirt’s fit, which can be immediately judged, benefits like “50% lower emissions” or “ethically sourced” are abstract and often require consumers to trust the brand’s word. This inherent difficulty in immediate verification makes brand credibility paramount. No brand wants to be accused of greenwashing—the practice of making unsubstantiated or misleading claims about environmental benefits—which can severely damage reputation and consumer trust. Our research suggests that explicit, fact-backed claims, under conditions of cognitive load, can paradoxically build this crucial credibility by offering a straightforward, seemingly confident message that reduces the mental effort required for evaluation.
The High Cost of Cognitive Load
Normally, when individuals possess the mental bandwidth to thoroughly evaluate information, they exhibit a strong preference for reaching their own conclusions. This active engagement allows them to feel more invested in their choices, viewing them as genuine personal opinions rather than external directives. Consider two friends recommending a restaurant: one meticulously lists beloved dishes and ambiance details, inviting you to decide if it aligns with your taste, while the other declares, "You have to go to this restaurant, it’s the best!" Most of us prefer the former, believing ourselves to be rational consumers who make up our own minds, even if behavioral economics often challenges this self-perception. When we have the luxury of time, patience, and mental energy, ads that present facts and allow us to infer conclusions are generally more appealing.
However, when cognitive load enters the equation, this calculation dramatically shifts. Imagine receiving that restaurant recommendation while simultaneously responding to urgent work emails, half-listening to a podcast, monitoring dinner on the stove, and navigating the general exhaustion at the end of a demanding week. In such a state, the mental effort required to assess detailed evidence becomes a burden. The friend who simply asserts, "Trust me, it’s the best," becomes easier to believe. Their confidence signals expertise and reliability, and the clarity of their directive offers a welcome relief from the mental strain, rather than feeling like an imposition.
This scenario precisely mirrors what occurs when people scroll through social media feeds. Their attention is fragmented, pulled in myriad directions by a mosaic of content: friends, family, acquaintances, celebrities, influencers, brands, and strangers. All these disparate elements compete fiercely for limited mental resources. When a sustainability-themed ad appears in this cognitively demanding environment, an explicit message like “it’s us” rather than “you decide” is not perceived as pushy. Instead, it registers as confident and trustworthy, precisely because users lack the mental capacity to engage in detailed independent verification.
The classic 1991 film "Father of the Bride" offers a humorous, albeit dramatic, illustration of how extreme cognitive load can impair judgment. Steve Martin’s character, under the immense stress of planning his daughter’s wedding, reaches a breaking point where his decision-making faculties are compromised, leading to an irrational, memorable confrontation over hot dogs. This cinematic moment, while exaggerated, highlights how easily stress and mental overload can lead even rational individuals astray.
It is a common human tendency, as research consistently shows, for every consumer to believe they are more rational and less emotional than others. While this might occasionally hold true, everyone experiences "foggy brain" moments. Our research underscores the critical importance of being in the right mental state when making online purchases, particularly for significant investments. Periods of high cognitive load or mental fatigue—such as late afternoons, later in the week, or immediately before a major event—are precisely not the ideal times for making important financial decisions. As a practical guideline, one should definitively avoid major purchases on a Friday afternoon at 4 p.m., when decision fatigue is likely at its peak. The recommendation is to defer such decisions until the following morning, when mental clarity is restored.
When Credibility Backfires: The Double-Edged Sword
While an explicit product claim can effectively signal credibility under conditions of high cognitive load, this strategy is a double-edged sword. Its effectiveness hinges entirely on the claim being rigorously backed by concrete evidence. Without substantiating facts, a bold, explicit claim can quickly devolve into what appears to be false advertising, severely damaging brand reputation. Worse, it can trigger a "boomerang effect," where consumers, feeling misled or manipulated, develop an intense aversion to the ad or even the brand itself.
Our studies meticulously ensured that explicit claims were always paired with real, specific facts—details about recycled materials, verified certifications, or quantified emissions reductions. This foundation of evidence is crucial. A brand that confidently asserts its superiority without demonstrable proof risks not only consumer distrust but also potential legal repercussions. Skepticism, once ignited, is notoriously difficult to extinguish and can cripple a brand’s long-term standing in the market. Companies like Volkswagen or BP have faced massive credibility crises when their claims did not align with reality, demonstrating the severe consequences of misrepresenting facts.
It is important to acknowledge the current limitations of our findings. While our research focused on sustainability messaging—a domain where verification is inherently challenging—it remains to be seen whether the same effect of explicit messaging holds true for other complex or opaque product categories. This could include ads promoting intricate health benefits, offering complex financial products, or detailing advanced technological features, all of which demand careful scrutiny from consumers. The digital age has unfortunately made it alarmingly easy for false or misleading messages to go viral, causing extensive damage before their claims can be adequately fact-checked. The diminished critical thinking capacity induced by cognitive load only exacerbates this vulnerability, making consumers more susceptible to misinformation.
For now, the overarching lesson for consumers navigating the relentless stream of social media is one of heightened awareness. If you find yourself scrolling, half-distracted, and an ad confidently declares a brand or product to be unequivocally "the best," pause. Recognize that this very confidence might be working on you precisely because your mental guard is down. To avoid the pangs of buyer’s remorse—or, in my case, the bewildered stares over dinosaur tear-away trunks—it is prudent to defer that late-night, cognitively-loaded purchase. Instead, heed the advice of research and wait until the clarity of the next morning to make your decisions.
Matthew Pittman, Associate Professor of Advertising and Public Relations, University of Tennessee
This article is republished from The Conversation under a Creative Commons license. Read the original article.
