AUSTIN, Tex.—The rise of the Web has caused a revolution in business—from music to journalism old models are buckling. And the upheaval is driven by the transformation of tangible goods into digital information in combination with fortuitous quirk of human nature.

That’s according to Clay Shirky, a new media scholar from New York University who spoke yesterday at the South by Southwest conference in Austin.

Shirky referenced Michael Tomasello of the Max Planck Institute who says that humans share three kinds of commodities: goods, services and information.

Imagine you are walking down the street and you see an elderly woman. She asks you for money. How would you feel? Now imagine that she asks you to help her cross the street. A different feeling. Now imagine she just asks for directions. A different feeling again.

It is this last case, the sharing of information, that humans do freely and actually want to do, according to Shirky.

Speaking about the demise of the music industry, he reminded us that we held on to our compact discs, goods we could touch. But when the music-sharing site Napster launched—and music became a digital file easily copied—sharing took off, and “the music industry freaked out.”

Shirky’s catchphrase serves as a guideline to predict future events: Behavior is motivation filtered through opportunity.

—Christie Nicholson