A recent McClatchy-Marist poll found that nearly 6 in 10 Americans think a nuclear disaster similar to what happened in March of this year in Japan could happen here. Why do so many people suddenly think that nuclear disaster is likely? Recent research in the Journal of Experimental Psychology: General might shed some light on the issue. 
In four studies, Joachim Vosgerau from Carnegie Mellon University showed that people’s judgments of the likelihood of events was strongly related to the way thinking about those events made them feel.

Relative to thinking about neutral events, when people are thinking about possible events that either are very desirable or undesirable, they experience an increase in arousal . When we think about the possibility of nuclear disaster near our home, we feel more agitated and emotionally aroused than when we’re thinking about the possibility of eating Mexican food for dinner.

Vosgerau found that people tend to attribute this increase in arousal to the likelihood of the event. In psychological terms, we’d refer to this as a misattribution of arousal. In other words, we figure that we must feel more emotionally aroused when thinking about nuclear disaster because it’s likely to happen. If it were unlikely, why would we feel emotional about it?

In light of this research, we may want to think twice when we start feeling panicky about things we read about in the news. We may feel like those things may happen to us at any moment, too, not because that’s actually true but because of a misattribution of arousal.

Vosgerau, J. (2010). How prevalent is wishful thinking? Misattribution of arousal causes optimism and pessimism in subjective probabilities. Journal of Experimental Psychology: General, 139, 32-48.