I worry that there are people who are put in positions of authority because they’re good talkers, but they don’t have good ideas,” he said. “It’s so … - Susan Cain

...the results have consistently suggested that introversion and extroversion, like other major personality traits such as agreeableness and conscientiousness, are about 40 to 50 percent heritable.

In fact, public speaking anxiety may be primal and quintessentially human, not limited to those of us born with a high-reactive nervous system. One theory, based on the writings of the sociobiologist E.O. Wilson, holds that when our ancestors lived on the savannah, being watched intently meant only one thing: a wild animal was stalking us. And when we think we're about to be eaten, do we stand tall and hold forth confidently? No. We run. In other words, hundreds of thousands of years of evolution urge us to get the hell off the stage, where we can mistake the gaze of the spectators for the glint in a predator's eye.

When you listen to music, you can transcend your own pain and turn towards another and feel bonded with the whole of humanity because you know that they have felt that grief and love. By expressing it, by communing with that song or picture, you realize you are not alone.