Sure, you could chant "I know I can" before tackling that first black-diamond run—or your big PowerPoint presentation. But according to Jeff Wise's book, Extreme Fear: The Science of Your Mind in Danger, tapping into your inner Wonder Woman may actually be an issue of matter over mind:

1. Get a hard body. In a study of novice skydivers, those with smaller percentages of body fat had less of the stress hormone cortisol in their bloodstreams before taking the leap. They also performed better on pre-jump cognitive tests.

2. Bundle up. A University of Wisconsin study reports that scuba divers dressed insufficiently for the cold water were likelier to panic in tough circumstances than those dressed in adequate wet suits.

What Do You Think?