If you broke ten bones before you turned twenty, it may not have been all your fault: Not only may extreme risk taking be genetic, but it may also make for a more attractive mate, evolutionarily speaking. "As our species evolved, communities with risk takers might have done better at things like warding off attackers," says a psychologist at the University of Colorado Denver. Risk taking comes from an adaptive gene: the people who jump from rocks without parachutes are also more likely to stumble upon the next big invention or run for office. This gene can be seen at work in the brain's amygdala, which processes emotion. Using fMRI imaging, neuroscientists at UCLA have shown that a tendency to put oneself in harms way originates in the amygdala by observing heightened activity in this region after eliciting fear in those who are proven risk takers, and, on the other hand, no activity for those who aren't.