Scientists Discover Tipping Point for the Spread of Ideas

An anonymous reader writes "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. '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,' said SCNARC Director Boleslaw Szymanski. 'Once that number grows above 10 percent, the idea spreads like flame.' The findings were published in the July 22, 2011, early online edition of the journal Physical Review E."

Comments

I don't think so

[suso]

This is bullshit and I will never believe it.

Re:I don't think so

[tenco]

Easy. Just make sure you choose the population size in which you want to spread your belief so that it's smaller than 10 x the magnitude of your followers. Once you've taken over, target a bigger population.

Modified Epidemiology

[mbone]

The authors (on a quick read of the original paper) are talking about a saddle point in the adoption of a new idea. This is basically the same as epidemiology, and their paper can be viewed as about a model of contagion in the case of infectious agents who can't be cured and don't die. So, in that sense this is like the classic result in epidemiology that an epidemic can't spread if the "basic reproduction number" is less than 50%. It's not magic, and it doesn't mean that if you get 10% + 1 acceptance is guaranteed, just where the tipping point is in this "modified epidemiology."

Re:Nonsense

[ObsessiveMathsFreak]

The idea may only need to be held by a small segment of the population; for example, the scientists in a specialised sub-discipline(~hundred or so people), the major media commentariat in a particular country of locality(~few hundred people), the academics in a wider field, e.g. economics (~few thousand people), or perhaps the opinions in a small sized nation.

I give you a good example: In Ireland (pop. ~4 million), the entire country went on a mad house buying binge, with the skeptics being ridiculed, ignored, or told by the nation's premier to go and commit suicide. Here's a retrospective blog post on the brazen insanity of those days. You'd kind of have to be from Ireland to get it all, but I think the Shamrock Island video explains itself.

Now, if you added up the people during the Celtic Tiger Boom who worked in the financial, construction, and property sectors, you'd pretty comfortably reach 400,000 people; ~10% of the population. And I can assure you that most of these people were indeed true believers in the idea that property prices would continue to grow forever. For any that weren't, the slack was picked up by overpaid public sector workers with property fetishes and the usual talking heads in the media. Ireland is a small country, so it was relatively easy to reach a 10% level in many sectors.

I stress that the eternal house price boom was a deeply held and virtually unassailable belief during the Celtic Tiger years. Skeptics were laughed at and ridiculed publically. Here's a quote from the article:

"The hyenas have stopped laughing . . . each and every one of them was wrong. Instead, the price and supply of housing units has continued to break records."
--Mr Dunne addresses the Society of Chartered Surveyors dinner in 2006

This was a few months after the country's major bank, Bank of Ireland, introduced 100%+ mortgages for buyers, which revved prices upwards again after the beginning of a brief slowdown.

This post is getting a little parochial, but to bring this back to the topic, I remind everyone that Ireland is now a bankrupted state in IMF hands, devastated by a massive property bust and credit crunch, with 5 out of 6 banks nationalised. This instance of "true believers" tipping over public opinion lead to the ruination of an entire country. I think its a good example of how the spread of ideas and ideologies can be damaging to societies, and why it's so important to challenge this spread in the early stages, because believe me, it's impossible to reverse things once the wildfire takes hold of the wider population.

Re:Did ayone read the paper?

[MajroMax]

Yes, I did read the paper. (Disclaimer: I have a PhD, but not in graph theory. Your results may vary.)

In short, the paper repeats analysis and numerical simulations of a simplified 'agreement model'. People are abstracted as nodes on a graph, communication happens between them, and consensus is reached. If a graph is initialized randomly, with nodes 'believing' either A or B, eventually (in log(N) time) the graph reaches consensus with every node 'believing' A xor B.

This paper adds a twist; some fraction of nodes are 'committed' to A, and cannot ever be convinced of B. To quote the paper:

Here, we study the evolution of opinions in the binary agreement model starting from an initial state where all agents adopt a given opinion B, except for a finite fraction p of the total number of agents who are committed agents and have state A. Committed agents, introduced previously in [23], are defined as nodes that can influence other nodes to alter their state through the usual prescribed rules, but which themselves are immune to influence.

Now, if even one node cannot be convinced of B, then no consensus can be reached -- but it doesn't really matter. If the fraction is really small, then you can more or less ignore them.

The interesting part about that paper is their threshold effect -- once p gets to be over 10%, not only does A eventually win, but it does so -quickly-.

The applications to politics still hold, but not on the big, obvious issues. Those issues, like taxes and abortion and health care and anything else that really makes the news, have committed believers on both sides -- they're outside the scope of study. Where this research becomes really interesting is in quieter, uncontroversial issues -- like regulation details, or climage change before Al Gore. There, this research suggests that the influence of sockpuppetry and lobbying is nonlinear -- beyond a critical point, the lobbyists completely win.

Of course, caveats about "the real world isn't an abstract graph" apply.