Accidental Brothers: The Story of Twins Exchanged at Birth and the Power of Nature and Nurture

The riveting story of two sets of twins separated at birth and improbably reunited as adults, a dream case for exploring nature vs. nurture.

Accidental Brothers tells the unique story of two sets of identical Colombian twin brothers who discovered at age 25 that they were mistakenly raised as fraternal twins—when they were not even biological brothers. Due to an oversight that presumably occurred in the hospital nursery, one twin in each pair was switched with a twin in the other pair. The result was two sets of unrelated "fraternal" twins—Jorge and Carlos, who were raised in the lively city of Bogotá; and William and Wilber, who were raised in the remote rural village of La Paz, 150 miles away. Their parents and siblings were aware of the enormous physical and behavioral differences between the members of each set, but never doubted that the two belonged in their biological families.

Everyone's life unraveled when one of the...