10 percent

Fascinating:

Scientists at Rensselaer Polytechnic Institute have found that when just 10 percent of the population holds an unshakable belief, their belief will always be adopted by the majority of the society. The scientists, who are members of the Social Cognitive Networks Academic Research Center (SCNARC) at Rensselaer, used computational and analytical methods to discover the tipping point where a minority belief becomes the majority opinion. The finding has implications for the study and influence of societal interactions ranging from the spread of innovations to the movement of political ideals.

[. . .]

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," said Associate Professor of Physics and 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."

I'll let you fill in your own joke about this explaining the crazy beliefs around today -- feel free to make fun of liberals or conservative or libertarian ideas depending on your philosophical predilection.

In all my years of expressing and responding to opinions, I've observed this tipping-point phenomenon many times. You listen to the debates on an issue for years and suddenly realize a new consensus has emerged -- that secondhand smoke must be banished from the public square, that humans cause global warming, that supply side economics is brilliant, that supply side economics is stupid, that trying to raise the debt ceiling that's been raised a hundred times in the last few years is now a looming crisis. I would have guessed the turnaround point was a lot higher. It's intriguing -- and a little scary -- if it really is only 10 percent.