"Most people (~80%) fall into the 'outer motivated instrumental reasoners' group. These people won't pick up an idea if other people aren't doing it. Which seems like a very wise evolutionary group tactic - if a little safe. Kay, in his ACM talk, uses a contagion or forest fire model to demonstrate/claim that around 66% of a population is needed to achieve 'ignition'. To hit the tipping point where 'everyone is doing it' and the new idea takes over."
