New York Times best-selling author of The Know-It-All and The Year of Living Biblically A. J. Jacobs undergoes a hilarious, heartfelt quest to understand what constitutes family - where it begins and how far it goes - and attempts to untangle the true meaning of the "family of humankind".

A. J. Jacobs has received some strange emails over the years, but this note was perhaps the strangest: "You don't know me, but I'm your eighth cousin. And we have over 80,000 relatives of yours in our database."

That's enough family members to fill Madison Square Garden four times over. Who are these people, A. J. wondered, and how do I find them? So began Jacobs' three-year adventure to help build the biggest family tree in history.

Jacobs' journey would take him to all seven continents. He drank beer with a US president, found himself singing with the Mormon Tabernacle Choir, and unearthed genetic links to Hollywood actresses and real-life scoundrels. After all, we can choose our friends but not our family.

Now Jacobs upends, in ways both meaningful and hilarious, our understanding of genetics and genealogy, tradition and tribalism, identity and connection. It's All Relative is a fascinating look at the bonds that connect us all.