Dan and Chip Heath, the team of brothers who wrote the best-selling book Made to Stick, tell the following story about a doctor who was trying to get his colleagues to practice proper hand-washing techniques:

[Dr.] Leon Bender became frustrated when he took a South Seas cruise and observed that the crew was more diligent about hand-washing than the staff at his own hospital. Frequent hand-washing by doctors and nurses is one of the best ways to prevent patient infections, and studies estimate that thousands of patients die every year from preventable bacterial infections.

Bender and his colleagues tried a variety of techniques to encourage hand-washing, but the staff's compliance with regulations was stuck around 80 percent. Medical standards required a minimum of 90 percent and [his hospital] was due for an inspection from the accrediting board. They had to do better.

One day, a committee of 20 doctors and administrators were taken by surprise when, after lunch, the hospital's epidemiologist asked them to press their hands into an agar plate, a sterile Petri dish containing a growth medium. The agar plates were sent to the lab to be cultured and photographed.

The photos revealed what wasn't visible to the naked eye: The doctor's hands were covered with gobs of bacteria. Imagine being one of those doctors and realizing that your own hands—the same hands that would examine a patient later in the day, not to mention the same hands that you just used to eat a turkey wrap—were harboring an army of microorganisms. It was revolting. One of the filthiest images in the portfolio was made into a screensaver for the hospital's network of computers ensuring that everyone on staff could share in the horror.

Suddenly, hand-hygiene compliance rose to nearly 100 percent and stayed there.

The Heath brothers conclude that we usually won't change our behavior until we see and even feel how we contribute to the problems in our world and in our relationships.