In 1924, two rich teenagers from the suburbs of Chicago murdered a kid in their neighborhood. They were caught right away, and the trial became known as the crime of the century. The gruesome story of Richard Loeb and Nathan Leopold became fodder for national newspapers and the inspiration for four films, several books, and one play.
During the trial, the killers’ parents hired two doctors, who tried to convince the judge that the boys weren’t responsible for their own actions. One doctor, using state-of-the-art tools of the time said he spotted a defective pineal (a gland in the brain) that triggered a lack of inhibition. Today we know the pineal gland emits bursts of melatonin that control our circadian rhythm, our internal clock. In other words, it has nothing to do with compelling someone to kill. In Leopold and Loeb’s time, it was connected ever-so-tentatively to sex and intellect. The doctor explained that because of Leopold’s hard pineal, he had too much libido, even for a 19-year-old boy, and not enough inhibition. In short, his hormones made him do it.
The judge said he was intrigued by this burgeoning field of endocrinology (the study of hormones), but these insights were not going to keep two murderers out of jail. The boys were each sentenced to life in prison.
For nearly a century, we have tried to use all kinds of tests to predict human behavior. Around the same time as the trial, Dr. Louis Berman, a New York City doctor, claimed he could look at people and figure out which of their many hormone-spewing glands controlled them. He labeled people “thyroid types” or “adrenal types,” based on some dubious assessment. He also said he could forecast their future — whether they’d become leaders, or movie stars, or criminals. Berman’s ambitions were lofty: He wanted to use his “skills” to evaluate school children and predict their futures. If a kid were destined for a wayward life, he’d prescribe preventive hormone therapy. He wrote books that the public adored and his colleagues loathed. Like many ideas based on conjure rather than data, his theory faded away.
We’ve tried for nearly a century to figure out ways to predict who is likely to be a killer, and then take extra cautions with those people. Last week, during a news conference about the flu epidemic, Alex M. Azar, the U.S. Department of Health and Human Services Secretary, began addressing the recent Florida massacre by saying that the administration needs to be “laser-focused on getting Americans with mental illness the help they need.”
That’s a nice idea. Those with mental health issues should get the therapy they deserve. We don’t need to stigmatize mental illness even further by assuming that anyone suffering from mental illness is a potential murderer. In a scientific article from 2015, published in the American Journal of Public Health, the authors write that the mentally ill are “far more likely to be assaulted by others or shot by the police than to commit violent crimes themselves.”
I’ve spent the past seven years exploring the history of hormones and the science of hormones and behavior. We’ve made great strides. We have more insight into the ways that hormones can make us moody or hungry or tired. We have hormone medicines that can help people with dysfunctional glands. But our notions of predicting a “killer instinct” are, at best, wishy-washy.
We are kidding ourselves if we think we can predict the next killer with tests based on hormones or surveys or any kind of chemical assessments. Politicians and others may look to these studies, because they provide a good sound bite, but we need to reread the history of medicine and the recent history of killing sprees to appreciate that it’s highly unlikely we are going to find the sure-fire predictive test and then provide all of the best preventative care necessary to prevent the next massacre.