One reason why it is so incredible to read these stories is that from the comfort of your own home, it is hard to envision whether you would have the courage to help out in the same circumstance. Yet, when you read interviews about people in these situations, they just report that they did what they felt was the right thing at the time.

Of course, one big difference between being at the scene of an event and reading about it later is the amount of time that you have to think about it. When you witness a or experience an earthquake, the situation unfolds quickly. You have to make a snap judgment about whether to take action. Reading about it later, you can think carefully about what you think is the right thing to do.

Joshua Greene and his colleagues suggest that when people are faced with moral dilemmas, there are two different reasoning systems that influence your decisions about what to do. One is a fast-acting emotion-based system that provides a gut reaction about how to act. In many cases that have a moral dimension, this system favors actions that fit with your responsibilities in the moment. The other is a slower reasoning system that allows you to take broader societal good into account.

In this case, choosing to push some people off the boat would save many at the expense of a few. However, pushing some people off the boat means that you have deprived those people of their right to try to survive as well.

A paper in the June 2011 issue of by Renata Suter and Ralph Hertwig explored whether people would give different responses to dilemmas like this depending on the amount of time they had to respond. In one study, people were told that they were going to read about a number of dilemmas Some were told that they should go with their first reaction and respond as quickly as possible. Others were told to think about the dilemma for as long as they needed to and then make a choice.

They found that people who could take as much time as they needed tended to make the choice that would save the most people at the expense of the few. That is, they would choose to push someone off the boat to save everyone else. In contrast, those who chose quickly, elected not to push people off the boat, despite the risk to everyone else.

These results support the idea that we reason about dilemmas in very different ways depending on the time we have to make the choice. In the moment, we are driven by a variety of emotions. At times, our choices in the moment seem humane (trying to save everyone or risking life and limb during a tragedy). Of course, those same emotions can cause us to lash out in at someone or to give into temptation in other circumstances.

When we have the time to justify our choices, we can reduce the influence of our emotions on the eventual choice. Whether this reason-based system leads to a good choice, though, depends a lot on the system of rules we adopt for making choices. Given enough time, we can probably talk ourselves into anything.

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