Still, the link between persistent, late bedwetting in childhood and future homicidal behavior endures. Dr. Kiehl thinks there could be a rational explanation for this.

Bedwetting is attributed to developmental delays in the neural circuits of the brain, and occasionally, that deficit is in a region of the brain called the amygdala. The amygdala enhances emotional learning, conditions us to fear, and amplifies stimuli around us. Studies have found connective and structural abnormalities in the amygdalae of criminal psychopaths.

“My hypothesis is that it’s the amygdala bladder circuit that is abnormal in youth who go on to commit homicide as adults,” Kiehl explained in The Psychopath Whisperer. “If that is the case, we need to revise the Macdonald Triad to indicate that the risk for future violence is present in chronic bed-wetting youth only if the circuit responsible is the one that passes through the amygdala…”