As hurricane Irene ripped up the East coast this weekend, the news media overflowed with dire warnings about all the terrible things that could happen. Transportation shut down and events were canceled. Even where the effects of the storm were comparatively modest.

Why are storm warnings so dramatic?

The answer, in a word, is fear. Fear is the most powerful motivator we have. It commands our attention like nothing else.

The news media, always looking for a way to attract eyes and ears, play on that fear with non-stop updates and dramatic predictions of awful consequences. The public picks up on the fear. Governments and corporations are forced to overreact in response, if only to defend themselves from criticism should they be seen as having taken the threat too lightly.

This is not to belittle those in coastal areas who really do need to evacuate their homes and rescue their boats. But hurricanes, unlike tornadoes, develop slowly enough that there is plenty of time for the fear machine to build.

We can’t help being subject to fear. But a key to keeping fear from undermining our happiness is learning to judge when threats are real or exaggerated by those who profit from scaring us.