Accidental Brothers: The Story of Twins Exchanged at Birth and the Power of Nature and Nurture by Nancy L. Segal and Yesika S. Montoya

c.2018, St. Martin’s Press

$26.99/$34.99 Canada

325 pages

There are more than 7 billion people in the world, and none of them are like you.

You are singular: nobody has your fingerprints, DNA sequence or thought processes. You’re you; one-of-a-kind. From follicles to toenails, there’s no other you anywhere … or so you think.

But as in the new book Accidental Brothers by Nancy L. Segal and Yesika S. Montoya – are you sure?

Three days before Christmas in 1988, 45-year-old Ana Delina Valesco walked four hours down a mountain path to catch a ride to the hospital. She was in pain from a hernia, and she was 28 weeks pregnant with identical twins. One of her boys was born very small, and would be taken by bus to a larger hospital in Bogotá, for treatment.

A day earlier, 36-year-old unmarried mother Luz Marina Chavez gave birth to identical twin boys in Bogotá’s Hospital Materno Infantil. It was a public facility; she chose it because she’d lost her insurance, despite that the hospital was “chaotic.”

It was chaotic enough that, at some point, Ana’s baby and one of Luz’s infants were accidentally switched.

Twenty-five years later, after a friend of a friend of one of the twins noticed that he resembled her co-worker, the switch was discovered: William was unrelated to his brother, Wilbur; Carlos was not Jorge’s twin.

Sorting details took a lot of work – how could they not? – and untangling took time and a toll on the young men. Two were raised in a comfortable environment, two were raised with very little. One set of twins was encouraged to get educations; the other set received just the basics.

Yet, despite differences in their raising, the identical twins’ similarities were striking; even their quirks and preferences were similar. Shortly after the twins learned of the switch, psychologist Montoya heard of it, too, and contacted Segal, director of California’s Twin Studies Center and herself a twin, with a unique opportunity.

Twins separated at birth are nothing new, Segal says; neither are incidents of swapping. But in this case, four men “were accidental players in a somber and stressful game of switch.”

Without a shadow of a doubt, Accidental Brothers is one of those books that’ll blow your mind. Only part of the explosion will come from the detective work authors Segal and Montoya share. Here, they explain how it was that no one noticed the switch when the boys were babies, why the families had unspoken suspicions and what happened during and after the life-changing accident was unraveled.

The other part of the ka-boom comes from Segal’s past work with twins in Minnesota and California . She explains how genetics affect our laugh, our quirks and our personal choices. We learn the many variations of twins, and how they happen. And she entertains with accounts of other twins she’s known and studied through the years.

This is a book for detective-story fans and for those who love a good scientific whodunit, and it’s an instructive tale, to boot. If you marvel at human uniqueness, then Accidental Brothers will be a singular delight.

Terri Schlichenmeyer has been reading since she was three years old and never goes anywhere without a book. She lives on a hill in Wisconsin with two dogs and 14,000 books.