According to a 2003 study,…

According to a 2003 study, slightly more than half of the men and 70 percent of the women knew of the five-second rule, and many said they followed it. That is, if you drop something on the floor and pick it up within five seconds, it's "clean" and you can eat it. Harold McGee investigates and formulates the five-second rule, version 2.0: "If you drop a piece of food, pick it up quickly, take five seconds to recall that just a few bacteria can make you sick, then take a few more to think about where you dropped it and whether or not it’s worth eating."