When a society is too grouped, people do not have any social contact with people from other groups,” Centola said. “People with the same job all attended the same school, live in the same neighborhood and frequent the same clubs. Their networks do not expand beyond that group.”

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.

“There’s a belief that the more that people interact with strangers, the more that new ideas and beliefs will spread,” Centola said. “What this study shows is that preserving group boundaries is actually necessary for complex ideas to become accepted across diverse populations.

Woodlice can calm their excited neighbors

Woodlice are able to calm their excited neighbors according to findings made by Pierre Broly and Jean-Louis Deneubourg of the Free Brussels University (Belgium).

Woodlice, familiar to the amateur gardeners, are easily observable living in groups sheltered under stones or barks. Research published in PLOS Computational Biology shows how a ‘contagion’ between the different behavioral states of woodlice may govern the stability of their groups.

By combining experiments and mathematical model, the authors show that calm individuals reduced the excitation of their neighbors which become calm in their turn. It results from this social influence that the bigger the group, the greater the proportion of calm individuals. Therefore the groups are more cohesive and slowly disperse when the group is perturbed.

Pierre Broly, Jean-Louis Deneubourg. Behavioural Contagion Explains Group Cohesion in a Social Crustacean. PLOS Computational Biology, 2015; 11 (6): e1004290 DOI: 10.1371/journal.pcbi.1004290



2015 Showcase

You know you're f*cked when...

Friend: do you know any good korean groups?

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me: *logs in into spazz sns accounts*

me: *opens all folders*

me: are you sure you’re ready for this conversation?