Richard Thaler’s Nobel Prize-winning nudge theory describes a nudge as a subtle intervention that increases the likelihood of a person making a specific choice or behaving in a certain way—often without their conscious awareness.

Nudges are typically easy to implement, respect individual freedom of choice, and can lead to significant changes in behavior, which explains their widespread adoption.

By altering the "choice architecture"—such as positioning healthier foods at eye level in a cafeteria or, as with RedCap, incorporating a calendar window on a traditional pill bottle cap—nudges make desirable actions more accessible and appealing. They leverage human preferences for simplicity and familiarity, making them a powerful tool in public health and policy to encourage positive behaviors while maintaining personal autonomy

Using pill bottles to nudge adherence

    • Organ Donation (Opt-Out Systems):
      Having human organs readily available at hospitals save lives. Yet, organ-donation remains a difficult issue in many societies, and their availability is scarce. In Austria, they solved this problem by applying the following nudge technique: the default option for Austrians is to donate organs automatically. Austrians are able to opt out of this program, but 99% consent to organ donation as a result of this nudge. By comparison, Germany has not used donate default, and organ donation is only 12%. In other words, Austrians must opt-out of donation while Germans must opt-in.

    • Calorie Transparency in Menus:
      Restaurants displaying calorie counts next to menu items nudge customers to make healthier choices. Studies show that this simple act reduces calorie consumption by 5-10% on average.

    • Hand Hygiene in Hospitals:
      Placing hand sanitizer dispensers in more visible, high-traffic areas and adding signs like "Help prevent infections—clean your hands!" increased compliance among healthcare workers by over 40%

  • Simplified Packaging

    • Prepackaged pill organizers labeled with the day and time (e.g., morning, evening). Depending on study, patients using clearly labeled packaging are 5-25% more likely to adhere to their medication schedule.

    Reminder Systems

    • Digital Reminders such as SMS or app notifications reminding patients to take their medication at the correct time. Example: A text that reads, “It’s 8 PM—time to take your blood pressure medicine.”

    Default Refills

    • Pharmacies automatically refill prescriptions and notify patients to pick them up which reduces gaps in medication adherence caused by delays in ordering refills.

    Habit-Forming Cues

    • Pairing medication with daily routines to associate medication with regular habits, like brushing teeth or eating breakfast. Example: "Place your pill bottle next to your toothbrush." Creates a consistent, automatic behavior over time.

A simple paint job that reduced car crashes by 36% 

The curve at Lake Shore Drive and Oak Street in Chicago is the city’s most dangerous, so the city naturally wanted drivers to slow down there. But as it turned out, fines and speed limits weren’t making a difference, as is often the case. So, the local government tried something different.

Instead, they admitted the fact that our rationality is bounded – we are not as rational as we like to think, and we are subject to plenty of cognitive biases. Therefore, addressing these biases with nudging could be more effective. So, they painted a series of white lines that gradually edged closer and closer together, giving the driver an illusion of speeding up. “Rather than asking people to slow down, the sensation of driving over these lines made the driver feel as though they were increasingly speeding up and at greater risk. Therefore, they naturally slowed down”. 

The city’s traffic engineers reported a 36% decrease in crashes in the six months after the lines were painted compared to the same 6-month period the year before.

A little fly etched in the urinal reduced “spillage” by 80%

The "urinal nudge" is a famous example of nudge theory applied to improve cleanliness in public restrooms. At Schiphol Airport in Amsterdam, a small image of a fly was etched into urinals, giving men something to "aim" at. This simple visual cue led to significantly less spillage and improved restroom hygiene. By subtly influencing behavior without instructions or restrictions, this nudge turned a natural human tendency into a positive outcome, demonstrating how small design changes can steer actions effectively.

Implementing this physical design change reduced spillage by 80%, and the budget for cleaning public toilets by 8%.