The Strength of Weak Ties

Anyone who’s read about social networks and the ‘tipping point’ will know how important the connections between people are. It’s not enough to look at just the number and the individuals in the connections though – you have to look at their strength. While reading an article (I forget which) about social networks, I spotted a reference to Mark Granovetter’s original 1973 paper on The Strength of Weak Ties (PDF).

This paper made an astonishing and counterintuitive claim – that weak ties between individuals are often more important than strong ties. To be clear, a strong tie might exist between family members or good friends, and a weak tie would exist between an old school friends who see each other once a year at Christmas. Granovetter’s paper is a little hard going for the first dozen or so pages, since it’s laden with a lot of theory and some specialised language, but it really gets going after that, when he starts quoting data:

In a random sample of recent professional, technical, and managerial job changers living in a Boston suburb, I asked those who found a new job through contacts how often they saw the contact around the time that he passed on job information to them…

Of those finding a job through contacts, 16.7% reported that they saw their contact often at the time, 55.6% said occasionally, and 27.8% rarely…

In many cases, the contact was someone only marginally included in the current network of contacts, such as an old college friend or a former workmate or employer, with whom sporadic contact had been maintained. Usually such ties had not even been very strong when first forged… It is remarkable that people receive crucial information from individuals whose very existence they have forgotten.

Remarkable indeed. Most people would approach friends for job leads first, not acquaintances, thinking that they would be more fruitful, but this is simply not the case (at least in general).

Towards the end of the papers is a wonderful section called ‘Weak Ties and Community Organization’. I recommend that you read it directly, since it’s written so well, but I’ll summarise below. Granovetter argues that when a community is completely partitioned into cliques, where strong ties vastly outnumber weak ties, it would be very difficult for that community to organise. Yes, you could provide news to everyone in the community, but would anyone do anything about it?:

Studies of diffusion and mass communication have shown that people rarely act on mass-media information unless it is also transmitted through personal ties… Enthusiasm for an organization in one clique, then, would not spread to others but would have to develop independently in each one to insure success.

This has powerful implications for communities shaped into cliques, such as the Italian community of Boston’s West End in the 50s and 60s, which was “unable to even form an organization to fight against the ‘urban renewal’ which ultimately destroyed it.” Weak ties are needed to allow information to spread between networks. Common sources of weak ties are clubs, work settings and formal organisations; so when you attend a conference every year, and simply spend a few minutes with a few dozen people there, you are refreshing those ties that allow information, gossip and job offers to spread.

Social networking sites like Facebook and LinkedIn allow you to formalise and track weak ties; that’s why they’re so powerful. Anyone who wants to emulate or learn from those sites would do well to look back to the original research conducted in this area.