In social networks, group boundaries promote the spread of ideas, study finds

The take away:

Loosening these tight group boundaries means that people's next-door neighbors may have different jobs or levels of education, but they may still have similar politics or recreational activities. These similarities allow people in different social groups to encourage the adoption of a new complex idea, take neighborhood recycling as an example, which can then spread to other neighborhoods and social groups.

But when group boundaries are eliminated entirely, people have almost nothing in common with their neighbors and therefore very little influence over one another, making it impossible to spread complex ideas.

I would argue it all comes down to how much 'trust' can be generated within a network. A network of people with lots of common similarities and easily shared traits will have a higher level of trust and therefore a greater propensity to share and receive more nuanced ideas/concepts. Large open and highly diverse networks of people will feel less 'trustworthy' or less 'comfortable' for people to contribute to or participate in.

The most effective networks have high levels of 'inner-trust' to generate ideas between participants, and cross-pollinating trust' to share ideas between networks.

To be honest, I don't find anything surprising about this, as what he describes is a traditional "small world" network (high clustering coefficient with short path links). The strong links within clusters efficiently amplify information, and the weak links between members of different clusters serve to transmit across the graph. (The fewer sparse cuts needed to decompose the graph, the less effectively you will be able to transmit data across it.)

For example, Milgram (1969) found in his famous letter-delivery experiment that the strongest predictor of success when sending a letter across ethnic lines was whether the first jump between ethnic groups was a "strong" or "weak" link -- weak links were significantly more likely to end in a successful transmission. This is almost certainly because ethnicity tends to be an accidental (due to uncontrollable historical factors) signal of socioeconomic group; weak ties are more likely to be across socioeconomic boundaries.

There may be more to the article than the press release indicates; Centola is a former MIT professor with a background in computational modeling, so I assume he brings something new to the table here.

Hacker News is a case in point. Its success and civility is due in large part to it being an enclave. Long time users and ycombinator itself has worried that it will be if not has already been a victim of its success as more and more of the general population is drawn to it.

Does politics count? Parties emerge in parliamentary democracies across a great many variations of the idea.