The 1989 James Woods/Robert Downey Jr. drama True Believer was tepid, scoring a 6.7 out of a possible 10 rating on IMDB. That makes it a slightly above-average movie, statistically speaking. But it's possible you or someone like you considers it one of the greatest legal dramas of the second half of the 20th century. And if you're enough of a true believer that you can infect 10 percent of the population with your belief, then that's exactly what True Believer is.
So goes the reasoning in the findings in a study of the spread of ideas conducted by researchers at Rensselaer Polytechnical Institute in Troy, New York (go Engineers). The research found that a reliable threshold of 10 percent exists in any of three types of social networks for an idea to thrive. When below 10 percent of a population holds a belief its spread is minimal, arrested. As one of the researchers put it: "It would literally take the amount of time comparable to the age of the universe for this size group to reach the majority." At or over that 10 percent threshold, however, and the belief spreads like wildfire.