The Jaws effect

And the surprising power of using vivid language to persuade people

Remember Steven Spielberg's blockbuster movie Jaws?

When Spielberg started shooting it he didn't have a finished script or a working shark.

Spielberg spent $250,000 on a mechanical shark nicknamed Bruce. 

But on the very first day of shooting the shark sank. 

And in less than a week Bruce's electric motor got damaged because saltwater got inside. 

Soon Spiel…