How social ties make us resilient to trauma.  Excerpt:

Hardening our society is one way to make us more resilient to hazards – that is, to allow us to bounce back from adversity more quickly. But we cannot armor our societies against all threats. Millions of people in cities like Boston, Mumbai, Ghana, Tel Aviv and Tokyo use public transportation systems, attend concerts, go to parks, visit malls and walk in public daily. All of these locations are vulnerable to those who would do us harm, and we cannot police them all. Further, protecting against one type of physical threat, such as an active shooter, does little to shield society against other types of dangers, such as vehicular attacks. My research on the role of social networks during and after crises provides an alternative approach. Rather than focusing on hardening our physical infrastructure, our societies become more resilient when we deepen and broaden our social infrastructure. Social ties provide emotional support, information and collective action at critical times.

Thanks to Dan Aldrich, the author, for calling this article to my attention.