Triad of Evil
Do three simple behaviors predict the murder-prone child? Post published by Katherine Ramsland Ph.D. on Mar 16, 2012 in Shadow Boxing

When twelve seals were shot and mutilated on Ireland's north shores in 2009, a commentator quipped that the perp had to be some kid honing his serial killer skills.

Thanks largely to misconceptions and spotty research, the notion that the Macdonald triad (animal cruelty, fire-setting, and bed-wetting) points to murder-prone kids has become an entrenched stereotype. This easy formula carries a heavy load, but it actually offers little for the prediction of criminality.

How did it gain the status of fact?


For a master's thesis, Kori Ryan submitted a study in 2009 that contradicts nearly half a century of claims. Ryan performed the most extensive review of the literature to date and found little empirical support for the triad's predictive value.