Centola, Damon, and Michael Macy. 2007. “Complex Contagions and the Weakness of Long Ties.” American Journal of Sociology 113 (3): 702–34. https://doi.org/10.1086/521848.

Notes

• The Strength of Weak Ties suggests that "whatever that has to be diffused" diffuses better with weak ties than strong ties but the article contends that argument
• Collective behaviors diffuse through social contact but when these behaviors are controversial, costly, or risky to participate, they require affirmations from multiple sources. this is called as complex contagion.
  • Grad students behavior in the union strike issue is a illustration of this phenomena where a student could require affirmation from multiple sources to participate in the strike since the participation is costly to their professional endeavors.
• “a small number of “seeds” can trigger a chain reaction of adoption, leading to a population-wide cascade of participation in collective behavior” (Centola and Macy, 2007, p. 705)
• threshold is the number of seeds required to trigger a change
• the threshold can have a wide upper range based on the characteristics of the change
• multiple exposures vs exposure to multiple sources
• “for complex contagions to spread, multiple sources of activation are required” (Centola and Macy, 2007, p. 707)
• Does negative seeds negate the efffects of positive seeds in activating the complex contagion?

Mechanisms of complex contagion

• “Strategic complementarity” (Centola and Macy, 2007, p. 707)
• “Credibility” (Centola and Macy, 2007, p. 708)
• “Legitimacy” (Centola and Macy, 2007, p. 708)
• “Emotional contagion” (Centola and Macy, 2007, p. 708)

In-text annotations

"As Granovetter puts it (1973, p. 1366), “whatever is to be diffused can reach a larger number of people, and traverse a greater social distance, when passed through weak ties rather than strong.”" (Page 703)

"Specifically, while weak ties facilitate diffusion of contagions like job information or diseases that spread through simple contact, this is not true for “whatever is to be diffused.” Many collective behaviors also spread through social contact, but when these behaviors are costly, risky, or controversial, the willingness to participate may require independent affirmation or reinforcement from multiple sources. We call these “complex contagions” because successful transmission depends upon interaction with multiple carriers." (Page 703)

"Weak ties connect acquaintances who interact less frequently, are less invested in the relationship, and are less readily influenced by one another. Strong ties connect close friends or kin whose interactions are frequent, affectively charged, and highly salient to each other." (Page 703)

"Granovetter’s insight is that ties that are weak in the relational sensethat the relations are less salient or frequent—are often strong in the structural sense—that they provide shortcuts across the social topology." (Page 704)

"a small number of “seeds” can trigger a chain reaction of adoption, leading to a population-wide cascade of participation in collective behavior" (Page 705)

"The distinction between multiple exposures and exposure to multiple sources is subtle and easily overlooked, but it turns out to be decisively important for understanding the weakness of long ties." (Page 707)

"for complex contagions to spread, multiple sources of activation are required" (Page 707)

"Network topologies that make it easy for everyone to know about something do not necessarily make it likely that people will change their behavior." (Page 728)

"Thus, consistent with McAdam (1986), our results show that the optimal networks for coordinating action will depend upon the costs and risks of participation." (Page 730)