Strength of Weak Ties

Granovetter's 1973 paper

In "The Strength of Weak Ties" (1973) the sociologist Mark Granovetter defined tie strength as a combination of time spent together, emotional intensity, intimacy and reciprocal services. Close friends tend to know one another, forming dense clusters that share much the same information. Weak ties, by contrast, often act as "bridges" between clusters, so news that circulates outside one's own circle arrives through them. In Getting a Job (1974) he surveyed professional, technical and managerial job changers in a Boston suburb and found that many who found work through contacts heard of it from people they saw only occasionally.

Extensions and critiques

Nan Lin and colleagues (1981) developed a social-resources theory in which weak ties lead to better jobs by reaching higher-status contacts. The idea underpins research on social capital and Ronald Burt's theory of structural holes. Critics pushed back. David Krackhardt (1992) argued that in uncertain, risky situations such as organizational change, trust-based strong ties matter more. Yanjie Bian (1997) found that in 1980s China strong ties carrying influence rather than information were more effective for job seekers. Centola and Macy (2007) showed that "complex contagions," behaviors that need reinforcement from several contacts, can be hindered by long weak ties.

Big data and causal tests

Analyzing mobile-phone records, Onnela et al. (2007) showed that removing weak ties fragments a network much faster than removing strong ones, confirming the bridging role of weak ties at scale. Gee et al. (2017) found on Facebook that an individual strong tie helps more with job finding than an individual weak tie, but because weak ties are so numerous most jobs still come through them. In a randomized experiment involving some 20 million LinkedIn users, Rajkumar et al. (2022) reported an inverted-U relationship: moderately weak ties, not the weakest, were most effective for job mobility. The theory also connects to small-world research and studies of labor markets.

FAQ

Are weak ties always better than strong ties?

No. Weak ties can be better for novel information, but many studies find strong ties matter more when trust, substantial help or risky decisions are involved.

What did the LinkedIn experiment show?

The 2022 Science paper provided causal evidence of an inverted-U relationship between tie strength and job mobility, with moderately weak ties having the largest effect.

Sources reviewed: 2026-10-26

References

1. Granovetter, M. S. (1973). The strength of weak ties. American Journal of Sociology, 78(6), 1360–1380.
2. Granovetter, M. S. (1974). Getting a Job: A Study of Contacts and Careers. Cambridge, MA: Harvard University Press.
3. Granovetter, M. (1983). The strength of weak ties: A network theory revisited. Sociological Theory, 1, 201–233.
4. Lin, N., Ensel, W. M., & Vaughn, J. C. (1981). Social resources and strength of ties. American Sociological Review, 46(4), 393–405.
5. Krackhardt, D. (1992). The strength of strong ties: The importance of philos in organizations. In N. Nohria & R. G. Eccles (Eds.), Networks and Organizations (pp. 216–239). Boston: Harvard Business School Press.
6. Bian, Y. (1997). Bringing strong ties back in: Indirect ties, network bridges, and job searches in China. American Sociological Review, 62(3), 366–385.
7. Burt, R. S. (1992). Structural Holes: The Social Structure of Competition. Cambridge, MA: Harvard University Press.
8. Onnela, J.-P., et al. (2007). Structure and tie strengths in mobile communication networks. Proceedings of the National Academy of Sciences, 104(18), 7332–7336.
9. Centola, D., & Macy, M. (2007). Complex contagions and the weakness of long ties. American Journal of Sociology, 113(3), 702–734.
10. Gee, L. K., Jones, J., & Burke, M. (2017). Social networks and labor markets: How strong ties relate to job finding on Facebook's social network. Journal of Labor Economics, 35(2), 485–518.
11. Rajkumar, K., Saint-Jacques, G., Bojinov, I., Brynjolfsson, E., & Aral, S. (2022). A causal test of the strength of weak ties. Science, 377(6612), 1304–1310.