The Tipping Point for Ideas: Implications for Infection Prevention Practices

Have you ever wondered what the tipping point is for the adoption of an idea? Scientists at Rensselaer Polytechnic Institute, members of the Social Cognitive Networks Academic Research Center (SCNARC), have discovered that when just 10 percent of the population holds an unshakable belief, their belief will always be adopted by the majority of the society.

“When the number of committed opinion holders is below 10 percent, there is no visible progress in the spread of ideas. It would literally take the amount of time comparable to the age of the universe for this size group to reach the majority,” says SCNARC director Boleslaw Szymanski. “Once that number grows above 10 percent, the idea spreads like flame.”

That might be something to bear in mind when you attempt to boost compliance with infection control practices such as hand hygiene.

An important aspect of the finding is that the percent of committed opinion holders required to shift majority opinion does not change significantly regardless of the type of network in which the opinion holders are working. In other words, the percentage of committed opinion holders required to influence a society remains at approximately 10 percent, regardless of how or where that opinion starts and spreads in the society.

To reach their conclusion, the scientists developed computer models of various types of social networks. One of the networks had each person connect to every other person in the network. The second model included certain individuals who were connected to a large number of people, making them opinion hubs or leaders. The final model gave every person in the model roughly the same number of connections. The initial state of each of the models was a sea of traditional-view holders. Each of these individuals held a view, but were also, importantly, open minded to other views.

Once the networks were built, the scientists then “sprinkled” in some true believers throughout each of the networks. These people were completely set in their views and unflappable in modifying those beliefs. As those true believers began to converse with those who held the traditional belief system, the tides gradually and then very abruptly began to shift.

“In general, people do not like to have an unpopular opinion and are always seeking to try locally to come to consensus. We set up this dynamic in each of our models,” says co-author Sameet Sreenivasan. To accomplish this, each of the individuals in the models “talked” to each other about their opinion. If the listener held the same opinions as the speaker, it reinforced the listener’s belief. If the opinion was different, the listener considered it and moved on to talk to another person. If that person also held this new belief, the listener then adopted that belief.

“As agents of change start to convince more and more people, the situation begins to change,” Sreenivasan adds. “People begin to question their own views at first and then completely adopt the new view to spread it even further. If the true believers just influenced their neighbors, that wouldn’t change anything within the larger system, as we saw with percentages less than 10.”

The research has broad implications for understanding how opinion spreads. “There are clearly situations in which it helps to know how to efficiently spread some opinion or how to suppress a developing opinion,” says co-author of the paper Gyorgy Korniss. “Some examples might be the need to quickly convince a town to move before a hurricane or spread new information on the prevention of disease in a rural village.”

The findings were published in the July 22, 2011, early online edition of the journal Physical Review E in an article titled “Social consensus through the influence of committed minorities.”