When an idea is accepted by 25% of the population, it becomes mainstream

How big do minority groups have to get in order to trigger these tipping points? Is it something like 30 to 40 percent, as Kanter and others have suggested based on sociological observations? Or is it as low as 10 percent, as physicists have predicted using mathematical models that simulate social change?

After running a creative experiment, Damon Centola from the University of Pennsylvania says that the crucial threshold is more like 25 percent. That’s the likely tipping point at which minority views can overturn majority ones.

He found that these newcomers were effective in changing minds only if they made up at least 25 percent of the total population. Anything less than that, and their suggestions never took off. Anything more than that, and their alternatives completely replaced the previous status quo. There was nothing in between.

He stresses that the 25 percent figure isn’t universal, and will likely vary depending on the circumstances. Indeed, the stakes in his experiment were very low. Volunteers jostled over arbitrary norms, rather than, say, politically charged beliefs. And both the established group and the incoming activists had similar amounts of power—something that’s rarely the case in real life.

This fits pretty well with research on individuals that finds they begin to question their views if more than 30% of their sources contradict their existing beliefs, which was a more emotionally charged situation :
https://plus.google.com/u/0/+RhysTaylorRhysy/posts/ct66PL7rdW7

I'll offer a few somewhat speculative generalisations :
- The amount of contrary information necessary will depend both (but not necessarily equally) on the amount of detail of an individual's purely analytic reasons for their existing conclusions and their emotional investment in an idea.
- Contrary information will have a greater impact coming from a trusted source.
- Contrary information can be designed to have a greater impact if targeted at specific individuals, e.g. in a way that doesn't undermine their identity, replacing their factual conclusions rather than shaping their underlying ideology. The latter can be changed, but it's more difficult.
- Thus the amount of contrary information required depends on quantity, quality, and source. Huge amounts of lousy propaganda won't work. Tiny amounts of brilliance won't work either, except to convince others to spread the ideas.
- Limits on the success of contrary information are not restricted to the above three criteria. It is also possible to inoculate individuals (or even better, whole groups, providing an ideological version of herd immunity via conformity) such that certain ideas have very little chance of infecting them because they're simply treated as evidence that the other side is biased. Everyone might hear an idea, but not everyone is equally susceptible. Thus, large groups holding highly polarised ideas can develop, each throwing around brilliant but ineffective propaganda.(https://plus.google.com/u/0/+RhysTaylorRhysy/posts/bNeHcmmh3iA).
- Within any population, some fraction will be susceptible or immune to lousy and brilliant propaganda, respectively. Thus there will always be a few idiots who believe in the Flat Earth and a few geniuses who believe, say, that Russia is a very nice friendly country that loves the West. I'll not guess what the statistical distribution of such beliefs looks like, but I bet it could be measured and usefully employed.
- Further to the above, individuals are tricky but populations can perhaps be predictable, somewhat. People may or may not be biological, programmable machines, but the end result for a population will be pretty similar to the case that they were. There is no idea that someone, somewhere, won't accept.
- Individuals can have vast numbers of ideas that aren't based solely on observable reality. This means that relatively small groups can come to believe things that someone might naively expect only a much larger group to have even thought of.


https://www.theatlantic.com/science/archive/2018/06/the-tipping-point-when-minority-views-take-over/562307/