The Myth of the Serial Killer Trio

For decades, experts claimed that bed-wetting, fire-starting, and cruelty to animals predicted future serial killers. Despite being famous in pop culture, modern science has debunked this theory.

This idea, known as the Macdonald triad, became a staple in true crime lore through shows and books. While these behaviors are certainly signs of childhood trauma, they are not reliable predictors of criminal adulthood. Most children who display these traits grow up to be well-adjusted individuals. It serves as a classic example of how a compelling story can sometimes overshadow rigorous scientific evidence.