In 1973, the soci­ol­o­gist Mark Gra­novetter pub­lished a paper called “The strength of weak ties” in which he put for­ward the idea that infor­ma­tion largely spreads through society between indi­vid­uals with weak con­nec­tions rather than strong ties.

His evi­dence came from asking a few hun­dred people how they found their jobs. It turned out that the most common route was through vague acquain­tances  rather than through strong friends.   Since then, Granovetter’s paper has become one of the most highly cited and influ­en­tial in the field of social net­work theory.

But what of the role of strong ties? Today, Marton Karsai and pals at North­eastern Uni­ver­sity in Boston show that strong ties can actu­ally hinder the spread of infor­ma­tion through a network.

These guys looked at over 600 mil­lion time-​​stamped  mobile phone calls between 6 mil­lion people over six months in an unnamed Euro­pean country. The analysis of these kinds of datasets has become common in recent years but Karsai and co have a new trick up their sleeves.

Read the article at MIT Technology Review →