What's the quickest way to ruin a friendship? Do great friendships have anything in common? Are close friendships in the workplace such a bad thing?

These are just a few of the questions that #1 New York Times bestselling author Tom Rath asked when he embarked on a massive study about the impact of friendships. Along with several leading researchers, Rath pored through the literature, conducted several experiments, and analyzed more than 8 million interviews from The Gallup Organization's worldwide database.

His team's discoveries produced Vital Friends, a book that challenges long-held assumptions people have about their relationships. And the team's landmark discovery - that people who have a "best friend at work" are seven times as likely to be engaged in their job - is sure to rattle the structure of organizations around the world.

Drawing on research and case studies from topics as diverse as management, marriage, and architecture, Vital Friends reveals what's common to all truly essential friendships: a regular focus on what each person is contributing to the friendship - rather than the all-too-common approach of expecting one person to be everything.

The book includes a unique ID code that provides access to the Vital Friends Assessment and website. This groundbreaking test reveals which friends play each of the eight vital friendship roles in your work and life.

Tom Rath's fast-paced and inviting storytelling takes a mountain of important research and makes it remarkably accessible and applicable. By the time you finish reading Vital Friends, you'll see your coworkers, family, friends, and significant other in a whole new light.