Laughter -- or silence -- is a classic manifestation of denial, as is delay. Zedeno was not alone. On average, Trade Center survivors waited six minutes before heading downstairs, according to a 2005 National Institute of Standards and Technology (NIST) study drawn from interviews with nearly nine hundred survivors. (The average would likely be higher if those who died had been able to respond to the survey.) Some waited as long as forty-five minutes. People occupied themselves in all kinds of interesting ways. Some helped coworkers who were disabled or obese. In Tower 2, many people followed fatal instructions to stay put. Staying inside was, after all, the standard protocol for skyscraper fires. But ultimately, the threat should have demanded immediate attention. Eventually, almost everyone saw smoke, smelled jet fuel, or heard someone giving the order to leave. Even then, many called relatives and friends. About one thousand individuals took the time to shut down their computers, according to NIST. "The building started to sway and everything started shaking," one person on a floor in the sixties of Tower 1 told NIST. "I knew there was something wrong." Notice what comes next: "I ran to my desk and made a couple of phone calls. I dialed about five times trying to reach my [spouse]. I also called my sisters to find out more information."
Why do we procrastinate leaving? The denial phase is a humbling one. It takes a while to come to terms with our miserable luck. Rowley puts it this way: "Fires only happen to other people." We have a tendency to believe that everything is OK because, well, it almost always has been before. Psychologists call this tendency "normalcy bias." The human brain works by identifying patterns. It uses information from the past to understand what is happening in the present and to anticipate the future. This strategy works elegantly in most situations. But we inevitably see patterns where they don't exist. In other words, we are slow to recognize exceptions. There is also the peer-pressure factor. All of us have been in situations that looked ominous, and they almost always turn out to be innocuous. If we behave otherwise, we risk social embarrassment by overreacting. So we err on the side of underreacting.
But it would be a mistake to assume that we just waste time during this delay.