Can You Fake Mental Illness?
How forensic psychologists can tell whether someone is malingering.
Illustration by Mark Alan Stamaty.
When someone commits a horrific, inexplicable crime, we naturally wonder whether he’s mentally ill: Who but a crazy person could do such a thing? But when a killer acts crazy after his arrest, we also might wonder whether he’s preparing for his trial. That’s the speculation around Colorado shooter James Holmes, whose psychiatric treatment and bizarre behavior in court and prison make people wonder whether he’s truly insane or building a case for an insanity defense. It leads to the question: Can a criminal get away with faking insanity?
Experts have been debating that question since the creation of the insanity defense in the mid-19th century. To avoid the noose or the guillotine, criminals of the era would fake symptoms from the then-emerging field of psychology. It soon became a cat-and-mouse game: Criminals would act out their understanding of insane behaviors, and alienists (the era’s term for psychologists) would write studies on how to detect those “malingerers.” Most techniques relied on the investigators’ experience and powers of observation—looking for inconsistencies in symptoms, waiting until the suspect tired of the game, or simply catching a telltale look in his eye. As the Austrian criminologist Hans Gross wrote: “The shammer, when he thinks no one is looking, casts a swift and scrutinizing glance on the Investigating Officer to see whether or not he believes him.”
Today, less than 1 percent of felony defendants raise an insanity defense, and a tiny fraction of those succeed. Yet in a state like Colorado, where proving insanity can avert a death sentence, the temptation to appear mentally ill must be strong. And so modern forensic psychologists, just like their forebears, watch for malingering with a sharp clinical eye. They determine whether the symptoms match those of well-studied pathologies and whether the signs remain consistent over time. They also can apply a battery of tests that essentially fake-out the faker.
The first step is to do a thorough review of the suspect’s history. Mental illness doesn’t develop overnight, so it’s important to know if the person has been hospitalized or treated for similar symptoms. The investigators also review the crime-scene report. If the suspect has hidden the weapon, washed off his fingerprints, or taken other steps to elude the police, it’s a sign of clear thinking—not mental illness.
Then come one or more long, rambling interviews—the longer the better, because after a few hours, some suspects begin to lose track of their symptoms or grow weary of the con. Phillip J. Resnick, professor of psychiatry at Case Western Reserve University, says he asks the suspect to talk at length about his history before saying a word about the crime, to lessen the chance of “retrofitting” a pattern of alleged illness to the deed. He and his colleagues listen carefully for signs of particular mental illnesses.
“Most malingerers don’t read the psychological literature,” says Tali Walters, a Boston forensic psychologist, so they present a Hollywood version of how a crazy person acts.
For example, some suspects claim to hear voices in their head that they’re powerless to resist, a commonly dramatized depiction of schizophrenia. Unlike what we see in the movies, most auditory hallucinations are benign; they seem to originate outside the head (not inside), and rarely come from aliens or other non-human beings. Only a small percentage are “command hallucinations,” and even fewer command a violent act. Furthermore, genuine schizophrenics find strategies to ignore these voices, or even make peace with them. They learn that certain activities, such as exercise, mute the voices; while others, such as watching TV, encourage them—the “voice” can’t seem to resist commenting on what it sees.
So if a suspect says he feels compelled to obey alien voices inside his head telling him to kill, there’s a good chance he’s feigning. Case in point: David Berkowitz, aka “Son of Sam,” who shot six people in a three-year murder spree in New York. Berkowitz claimed that he was following the commands of a demon-possessed Labrador retriever, but later admitted it was a hoax. “A dog,” says Resnick, “is not a typical [auditory] hallucination.”
Malingerers often exaggerate their symptoms and ignore common, subtle signs such as the blunting of a mentally ill patient’s emotions. Some fakers say one thing and do another. They might feign confusion to the psychiatrist but later converse easily with cell-mates, or claim to be paranoid while sitting at ease. Some combine symptoms from different conditions, such as hallucinations of schizophrenia and obscene outbursts found in Tourette’s syndrome. The forensic psychologist may suggest an outrageous delusion during the interview, such as, “Do you believe cars are part of an organized religion?” Fakers might latch onto this bait and perhaps even run with it. Real schizophrenics would say no.
At some point the examiner leads the discussion to the crime, which sets another trip-wire for deceivers. No matter how delusional the suspect claims to be, the crime scene must fit the hallucinations he describes. It’s hard to believe a suspect who says he was slashing wildly with a kitchen knife against an army of aliens when he actually left a single stab wound in his mother’s chest. Another clue is a cover story that conveniently mixes delusion and reality.
Douglas Starr is co-director of the graduate program in science journalism at Boston University and author, most recently, of The Killer of Little Shepherds: A True Crime Story and the Birth of Forensic Science.