3 THEORY AND RELATED STUDIES
3.4 Strong and Weak Ties
3.4.3 Six degrees of separation
In 1967 Stanley Milgram, a social psychologist, conducted what is known as the ‘small world’ experiments. In his experiments he focused on network structure and, among other things, asked people to pass on a letter in an effort to reach a targeted individual. Although very few of the letters reached its destination, the ones that did had only passed through about six people. It is this number of links that determines the smallness of the world, making the world smaller or larger depending on how many links that separate two random people.
Milgram’s experiments later became the basis of the notion Six Degrees of Separation29. Although Milgram never used the phrase himself, he is usually credited the idea (Garfield, 1979; Newman, 2003).
In retrospect, a number of researchers have conducted experiments resulting in similar conclusions. For example, Dodds, Muhamad and Watts (2003) conducted an experiment30 testing the degrees of separation as participants tried to reach certain targets through the use of e-mail. They estimated that the number of chains varied from five to seven people, in addition to pointing out that the success was very dependent on the activity and motivation of the participants. Furthermore, Killworth et al. (2006) made a study of the accuracy in small world chains, suggesting that chains vary from two or three to 14 chains depending on whether or not people chose the ‘right’31 paths in their social network. If the right paths were to be chosen, however, they estimated a maximum total of 5 chains. It is important to note that the study was based on telephone surveys32 in addition to being work-related, meaning that the
29 In short, the theory of Six Degrees of Separation is that, on average, the number of weak ties that link two random people is six (Garfield, 1979; Newman, 2003). The phrase ‘six degrees of separation’ became a popular notion after playwright John Guare introduced his play Six degrees of Separation in 1990 (Newman, 2003).
30 The experiment is called the ’Small World Project’ and is an online experiment. People can visit the website
<http://smallworld.columbia.edu/> and sign up as participants.
31 According to Killworth et al. (2006) the ‘right’ choice is defined as choosing the shortest possible path.
32 The network that was analysed consisted of 105 members of an interviewing bureau, with a total of 10,920 possible paths. The participants had full knowledge of all available chains and were not asked to make choices about the next step in the chain (Killworth et. al., 2006).
results might not be representable in relation to global social networks (Killworth et. al., 2006).
Granovetter’s hypothesis of weak ties, and especially local bridges, was also tested by Noah Friedkin in his article “A Test of Structural Features of Granovetter’s Strength of Weak Ties Theory” (1980). What Friedkin found was that all local bridges indeed consisted of weak ties and that the removal of such bridges would cause the most damage to the possibilities of a person’s social network, supporting Granovetter’s theory from 1973. The removal of an equivalent number of strong ties was, on average, was found to have no consequence regarding the size of a person’s social network (Friedkin, 1980). However, Friedkin also emphasized that even though local bridges theoretically represent the shortest path between two people, they do not necessarily represent the most likely path.
“Granovetter’s theory, to the extent that it is a powerful theory, rests on the assumption that local bridges and weak ties not only represent opportunities for the occurrence of cohesive phenomena (e.g., information and influence flows, intergroup coordination and mobilization, etc.) but that they actually do promote the occurrence of these phenomena” (Friedkin, 1980: 421)
The fact that any two individuals might be connected through six degrees does not necessarily mean that they benefit from their connectedness.
It has been said that the Internet might decrease the number of weak ties. This is based on the assumption that the Internet makes it easier to get in touch with people from all over the world due to the loss of social cues such as geography, social status and so on. Low cost applications like e-mail and instant messenger also makes it easier to keep in touch (Adamic and Adar, 2005; Baym, 2006). In addition, through social networking services, the Internet might make it easier to map out one’s connections and discover how many chains that separate individuals. People might only be a few steps away from each other without even realizing it, and these services allow them to discover how they are connected and through whom (Adamic and Adar, 2005). As such, the Internet does not necessarily diminish the number of chains, but it makes them more visible, which makes it easier to choose the ‘right’ paths.
Boyd and Ellison (2007) also emphasize that social networking services, such as LinkedIn, may provide a bridge between online and offline social relationships, and that they are
particularly useful in relations to the maintenance of weak ties (such as former classmates or colleagues). They also report that this is one of the main differences between social networking services and other forms of CMC.
It is important to note that Granovetter’s theory of weak ties will probably never be proven or discarded due to issues of how to define a weak tie and measuring difficulties (it is probably impossible to measure all the global chains a person has). Additionally, it is important to keep in mind that the theory of six degrees is based on weak ties, meaning that when two people are six weak ties apart they are usually also six social networks apart (Adamic and Adar, 2005; Pickering and King, 1995). The distance is therefore of much greater length than it might sound like. As Adamic and Adar (2005) emphasize, the number of random acquaintances a person has is estimated to vary from 500 to 1500. With an average of 1000 acquaintances it would only take about 2 intermediates in order to reach a network at the size of the United States (Adamic and Adar, 2005).