Mary King, a member of the sociology and anthropology faculty, is an expert on how communities and individuals weigh danger and risk when making decisions. She says that a major disaster, such as the recent flooding along the Mississippi River or the devastating tornado in Joplin, Mo., forces a community to reexamine its perception of risk as it works to recover from a tragedy.

Does a disaster bring people together? Or does it create further divisions?

It depends. There are many, many instances of people who, in the aftermath of a disaster, behave extremely cooperatively. This tends to happen when there are no visible signs of relief coming. They tend to really work with their neighbors, work with the people surrounding them to allocate the immediate needs of the group. In New Orleans after Hurricane Katrina, there were instances where people helped to get formula and diapers to infants and helped to get water for elderly people.

But that is not always the case. In New Orleans after Hurricane Katrina, there were also some who attacked people they didn’t know.

Why are some communities, or members of a community, able to recover more quickly from a disaster than others?

All the inequalities that exist in these particular instances before a disaster just get exacerbated after one. In the aftermath of those disasters, questions emerge: Why are some neighborhoods preserved while some are not? Why is one house rebuilt while another is not? You’d like to say that these communities are going to come together, and in some ways they will. But some inequalities are going to be further displayed and exacerbated by this kind of event.

If I’m wealthy and I lose a home, I might have insurance or some other means and I can start over. But if I’m less than wealthy, if I’m a person who is struggling and I lose my job and I’m injured and my house is destroyed, I’ve lost everything. How a disaster happens may cause more inequality in the end.

How does a community’s perception of a disaster change after a devastating event occurs?

Risk evolves as a social construct within a larger notion of society, in which people hold each other mutually accountable. When something unexpected happens, people tend to feel really betrayed by the institutions that are supposed to protect them, even though that’s an imaginary safety net that we all walk around in.

The idea of risk evolves in the aftermath of a disaster. Before a disaster, risk exists solely as something that has to do with chance. People might say, “It was God’s will,” or whatever. But a disaster really changes how people perceive risk in the aftermath. People have to be held accountable.