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Misapplied behavioural science: how oversimplification undermines the field
Behavioural science has gained considerable traction in policy and business circles over the past decade. Its appeal lies in the promise of subtle interventions—“nudges”—that, in theory, can produce meaningful changes at minimal cost. Yet this very promise, while grounded in sound principles, has led to the oversimplification of much more complex challenges.
I'm going to illustrate this with an intervention spotted in the wild at my local airport, Amsterdam Schiphol, to show how, without understanding the deeper context and motivations behind behaviour, such interventions often fail to address the real drivers of action.
This is a follow-up to a previous article about the false promise of superfoods, nudges and other quick fixes.
The behavioural challenge
Schiphol Airport has been grappling with a persistent issue: drivers using the departure zone for quick pick-ups instead of the designated short-term parking. Over the past couple of years, the airport has introduced various measures to discourage this behaviour, such as placing signage reminding visitors of pick-up areas and deploying parking wardens during peak times to instruct drivers to move if they linger too long.
Despite these efforts, the behaviour persists. The structural incentives—saving time, avoiding parking fees, and minimising walking distances—remain firmly in place. Frequent travellers and locals familiar with Schiphol’s layout have adapted, often ensuring passengers are waiting at the curb for near-instantaneous pick-ups.
The reasons for this persistent behaviour are straightforward but deeply embedded in rational incentives. Short-term parking at Schiphol comes with a fee that frequent travellers and locals, familiar with the airport’s layout, see as unnecessary for a quick pick-up. The layout of the parking lot adds further frustration. Even after parking, both passengers and drivers face long walks through Schiphol Plaza—a crowded space full of shops and passengers heading to and from the train station.
For arriving passengers, especially frequent flyers, the motivation is clear: get home as quickly as possible. The idea of walking across the plaza after a long flight only adds time and stress to an already tiring journey. Picking them up at the departure zone provides a way to shave off those extra minutes and get them home faster.
These motivations—saving time, avoiding fees, and minimising walking distances—continue to drive the behaviour. Schiphol’s challenge isn’t just about enforcing rules; it’s about addressing the underlying rational incentives that make the departure zone an attractive alternative for pick-ups.
The "Watching Eyes" intervention
In response to the persistent pick-up behaviour at the departures zone, Schiphol installed images of eyes designed to evoke the "watching eyes" effect. The idea was simple: people are more likely to comply with rules when they feel observed, even by something as minor as an image of eyes.
This "watching eyes" effect stems from studies suggesting that people exhibit more prosocial behaviour in the presence of eye-like stimuli. However, these studies relied on very specific conditions for success:
Low-stakes environment: The original experiments were conducted in settings where non-compliance carried minimal risk (e.g., coffee rooms).
Absence of real observers: The effect was most pronounced when no actual people were present, relying on a subtle, psychological illusion of being watched.
Prosocial behaviour: The behaviours in question were socially desirable, leveraging people's sensitivity to reputation management.
None of these conditions apply at Schiphol. The airport is a high-stakes environment where drivers face real consequences, such as fines or missed passengers. Real observers—parking wardens—are already present, making the symbolic "watching eyes" redundant. Moreover, the target behaviour at Schiphol is not about prosociality but efficiency and rational cost-saving, with strong incentives to minimize waiting times and avoid fees. These powerful motivations easily outweigh any perceived social pressure from symbolic eyes.
In short, the "watching eyes" intervention was unlikely to succeed from the outset.
This case illustrates a fundamental lesson in behavioural science: interventions that work in controlled, low-stakes environments can fail dramatically when applied to complex, real-world scenarios with very different motivators and constraints. Relying on nudges without fully understanding the context risks not only ineffective interventions but also a deeper misunderstanding of what drives behaviour in the first place.
Moreover, Schiphol’s intervention failed to address the root causes of the behaviour. Instead of considering structural solutions—like redesigning pick-up areas or reducing parking fees—the airport opted for a quick, low-cost nudge that was ill-suited to the real problem. This approach neglected the rational incentives driving the behaviour and focused on superficial compliance.
The broader issue of misused behavioural science
The case of Schiphol's "watching eyes" intervention, while notable, reflects a wider issue: the frequent misuse of behavioural science across sectors. Nudges, like the "eyes" experiment, have gained popularity for their perceived ability to solve complex problems with minimal effort. However, as Schiphol demonstrates, relying on these superficial interventions often produces subpar results.
This misuse typically manifests in several ways:
Oversimplification of complex problems: Nudges are often treated as quick fixes for deeply entrenched behaviours without addressing the underlying structural factors.
Neglect of structural solutions: In many cases, decision-makers bypass more meaningful interventions—such as improving infrastructure or incentives—in favour of a nudge that promises an easier win.
Misunderstanding context: Behaviour is always context-driven. Without considering the specific environment and motivations behind actions, even the best-intentioned interventions can fail.
Overestimation of effects: There is a misconception that nudges can create significant, long-lasting change on their own. In reality, their impact is often overstated.
Schiphol’s reliance on the "watching eyes" effect reveals a deeper problem: the assumption that nudges are universal, one-size-fits-all solutions. Behavioural interventions are highly context-specific, and when applied without a thorough understanding of the motivations behind the behaviour, they’re bound to fail. Here, the behaviour is rational: drivers and passengers are optimising for time, convenience, and cost. It isn’t a matter of antisocial tendencies or prosocial motivation.
The same "eyes" intervention has been used in the UK to deter littering, with posters depicting eyes meant to evoke the feeling of being watched. However, like at Schiphol, these interventions have often fail because the context undermines their effectiveness. (Arguably, the use of cartoon and animal eyes in some of them highlights the lack of understanding of what is theoretically meant to make this effect work!)
Schiphol could have addressed this with a structural solution. Many airports have created fast pick-up zones near arrivals, reducing congestion and offering a convenient alternative for drivers and passengers. This would have tackled the real incentives behind the behaviour. Instead, Schiphol opted for the "eyes" nudge—a simple intervention that overlooked these deeper motivations.
This decision reflects a common mistake: the belief that small nudges can produce significant behavioural change without addressing the broader context. When nudges don’t align with real-world incentives, they rarely succeed. In Schiphol’s case, a fast pick-up zone would have directly addressed the underlying drivers of the behaviour—time, cost, and convenience.
Consequences of misapplied behavioural science
Misapplied behavioural science doesn’t just lead to ineffective outcomes—it can undermine the field's reputation and long-term effectiveness. When decision-makers implement interventions without fully understanding the context, the consequences are often far-reaching, wasting resources and eroding trust.
Here are the most significant impacts of oversimplified, poorly designed interventions:
Wasted resources and opportunity costs: Time, money, and effort are invested in failed interventions that could have been directed toward more effective solutions. In Schiphol’s case, resources used on the "watching eyes" nudge could have gone to addressing the real drivers of behaviour, such as improving the structure of pick-up zones or rethinking parking fees.
Erosion of credibility: When high-profile behavioural interventions fail, the entire field suffers. This fosters skepticism among stakeholders, who may dismiss future, well-designed interventions due to past disappointments.
Misaligned expectations and intervention fatigue: The overselling of nudges as quick fixes creates unrealistic expectations. When these interventions fall short, people become disillusioned, leading to resistance or apathy towards future interventions—regardless of their merit.
Neglect of structural solutions: The reliance on nudges can distract from more systemic changes. At Schiphol, rather than addressing the logistical inefficiencies (like inconvenient parking), the focus remained on a simple nudge that failed to tackle the core issue.
Damage to professional growth: As demand for quick, low-cost behavioural solutions grows, the field risks becoming associated with gimmicky interventions rather than rigorous, evidence-based work. This can stunt the professional development of practitioners, reducing opportunities for more meaningful, complex projects.
The consequences are clear: superficial fixes lead to wasted resources, eroded trust, and missed opportunities for real change. To move forward, we need to rethink how we apply behavioural science—starting with more context-driven, nuanced approaches.
Why applied behavioural science needs expertise
Schiphol’s "watching eyes" intervention is just one example of a recurring issue in behavioural science: the overselling of nudges as quick fixes. Nudges are often marketed as low-cost, simple solutions to complex problems, with the idea that small cues, like images of eyes, can drive big changes without significant investment. But just like adding goji berries to a poor diet won’t transform your health, nudges fail when they don’t address the deeper context behind behaviour.
Behavioural science is frequently oversimplified by non-experts, who believe that a single nudge can solve complex behaviours. This leads to poorly implemented interventions that, when they fail, give the impression that the field itself is ineffective. For practitioners, this means fewer opportunities, less trust from stakeholders, and a growing challenge to prove the real value of behavioural science.
Effective behavioural change demands more than clever nudges—it requires understanding the underlying motivations and incentives. Using nudges like "watching eyes" to tackle deeply ingrained behaviours is like applying a band-aid to a bullet wound. When such band-aids inevitably fail, they erode trust in the field, making it harder for experts to advocate for better, more nuanced solutions. In some cases, behavioural science may be seen as irrelevant, leaving practitioners out of the conversation entirely.
Ultimately, if we continue to push quick fixes, we risk undermining the credibility of behavioural science—and missing the chance to create real, lasting change.
Note on the image of fly tipping example on the cover of the post: the image used here is AI-generated, but I had originally taken a similar picture in Reading (UK) earlier this year, but sadly I can no longer find it - in the original, the rubbish was piled directly under the sign.
Selected further reading:
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