The media often portrays serial killers as evil geniuses, tricking their victims and
evading law enforcement for years, all without arousing suspicion from the people around
them.
But how smart do you really need to be to get away with murder?
Is the IQ of the average serial killer really higher than that of the rest of the population?
Hi, I’m Justin Dodd.
The idea that the most prolific murderers boast exceptional intelligence is one of several
misconceptions about serial killers I’ll be debunking today, from their supposed obsession
with sex to the efficacy of criminal profiling.
Let’s get started.
IQ tests administered in several murder cases have found that the perpetrators of these
crimes aren’t any smarter than the general population.
The average serial killer IQ falls around 95, while anything between 90 and 110 is considered
typical.
Murderers who are able to cover up their crimes are usually driven by an obsessive nature,
but that isn’t necessarily a marker of intelligence.
This myth about superior intelligence may have contributed to the idea that serial killers
only get caught “because they want to.”
But that’s probably not quite right, either.
According to the FBI’s website: "As serial killers continue to offend without being captured,
they can become empowered, feeling they will never be identified.
As the series continues, the killers may begin to take shortcuts when committing their crimes.
This often causes the killers to take more chances, leading to identification by law
enforcement.
It is not that serial killers want to get caught; they feel that they can’t get caught."
Hubris, gets 'em everytime.
Certain kinds of serial killers do tend to be smarter than others.
According to one analysis, murderers who used explosives had an average IQ of 140, which
is considered superior intelligence.
Perpetrators who used the more direct approach of bludgeoning came out below the national
average at 79 points.
All Serial Killers Have Dozens of Victims
When you hear the term serial killer, you likely think of a long Wikipedia page and
a victim count in the double digits.
But while murderers who check those boxes get the most attention, they're far from typical.
According the FBI’s definition, criminals need to kill a minimum of two people to be
considered serial murderers.
It doesn’t matter if the victims were unlucky hitchhikers or rival gang members—the killings
just need to be two separate incidents, and there has to be a “cooling off” period
between them.
By this definition, there are probably more serial killers out there than people may assume—they’re
just not prolific or idiosyncratic enough to warrant a creepy nickname or their own
Netflix series.
When the general public hears about a person who commits multiple murders, they’re apt
to say the culprit is mentally disturbed.
That may be true in the colloquial sense, but it isn’t the same thing as legally being
declared clinically insane.
And it risks painting people who suffer from mental illness with an unfair and misleading
brush.
There are a few different tests for the Insanity Defense to hold up in court, but the most
famous is if the defendant is determined to have been mentally incapable of understanding
the gravity of their actions when committing the crime.
Under this strict definition, very few murderers qualify as legally insane.
When serial killers do have mental disorders, they rarely suffer from the psychotic conditions
that pop culture conflates with violent behavior, such as schizophrenia.
As Scientific American explains: "Serial killers are much more likely to exhibit antisocial
personality disorders such as sociopathy or psychopathy, which are not considered to be
mental illnesses by the American Psychiatric Association.”
People with these conditions may exhibit a lack of empathy or remorse, but they are still
intellectually capable of distinguishing right from wrong.
These disorders can also be difficult for outside observers to spot, as many people
with personality-related disorders are high-functioning and adept at performing socially accepted
behaviors.
And, of course, not everyone diagnosed with serious mental illness commits violent crime.
Studies have found that patients with severe mental illnesses only show significantly higher
rates of violence in connection to substance abuse.
This suggests that the comorbidity of drugs and alcohol with mental illness is a better
predictor of violent crime than the conditions alone.
A fact that you may not have heard is that people with schizophrenia are much more likely
to fall victim to violence than the general population, and the stigma around this disorder
may contribute to that troubling trend.
The act of serial killing is often portrayed as an addiction in popular media.
Once the perpetrator gets a taste for murder, you would think they were incapable of stopping.
In reality, some serial killers have been known to quit their criminal habits.
The FBI cites Dennis Rader, or the BTK killer, as an example.
After killing 10 people between 1974 and 1991, he seems to have stopped.
Rader was arrested in 2005, apparently 14 years after his last murder.
Sometimes a change in circumstances, like a move or a marriage, can interrupt a serial
killer's life of crime.
In other instances, they're able to find an outlet for potentially violent compulsions
in consensual or solitary sexual activities.
That brings us to our next misconception: All serial killers are driven by sexual urges.
This idea comes from the fact that many of the most famous serial killers sexually abused
their victims, including Albert Fish, Ted Bundy, and Jeffrey Dahmer.
There is indeed a sexual component to many serial killings, but sex isn't the only reason
these crimes happen.
Greed is another common motive.
H.H. Holmes, a serial killer who operated in Chicago in the late 19th century, amassed
wealth through his murders by taking out insurance policies on his victims and stealing their
property.
Some killers seek excitement or an outlet for anger.
This was likely a factor in the D.C. sniper killings of 2002, during which John Allen
Muhammad and Lee Boyd Malvo shot 13 victims, killing 10 of them.
It’s easy to see why serial killers are so often painted as social outcasts.
If someone is capable of breaking a taboo as serious as, you know, murder, it’s hard to imagine
them functioning as a normal member of society.
But many serial killers lead seemingly normal lives before they’re apprehended—seemingly
being the key word.
The FBI writes in its report on serial murder that “the majority of serial killers are
not reclusive, social misfits who live alone.”
Many of them have families, neighbors, and coworkers who would never suspect them of
violence.
The ability of many serial killers to lead apparently normal lives sometimes explains
how they’re able to get away with their crimes long enough to kill multiple times.
When it comes to their criminal activity, most repeat murderers do like to fly solo.
But not every serial killer is a lone wolf by definition.
Approximately 10 percent of these offenders kill in groups of two people or more.
So even when the well-adjusted facade is down, a significant number of killers prefer collaboration
over isolation.
Ya know what they say, team work makes the… murder.
It’s true that serial murder is a male-dominated field—and one that most women presumably
aren’t eager to break into.
Nearly all of the most famous criminals in this category from the past century-and-a-half
are men.
But that doesn’t mean female serial killers are nonexistent, or even that rare.
According to a 2015 report from experts at Florida State University, go noles, and the
California School of Forensic Studies, roughly 16 percent of America’s serial killers are
women.
According to Scientific American, women are responsible for about 10 percent of all murders.
That means “women represent a larger percentage of serial murders than all other homicide
cases in the U.S.”
Female serial killers are more likely to poison their victims.
A greater proportion of them work in health care, where they kill by giving lethal overdoses
to patients.
And the women who commit serial murders more commonly work as part of a pair or team, unlike
the “lone wolf” killers the media likes to endlessly discuss and, at times, even glorify.
There's an entire genre of crime television that relies on the misconception that criminal
profiling works.
In such shows, investigators are able to determine personal details about a serial killer—from
their age to their relationship with their parents—just by analyzing a murder scene.
This process makes for good TV, but it may be a waste of time in real life.
According to a 2007 meta-analysis published in the journal Criminal Justice and Behavior,
criminal profilers are just marginally better at guessing quote, “offender characteristics”
than non-professionals.
Even when profilers do come up with accurate predictions, it doesn't tend to make much
of an impact on the case.
Criminal profiling rarely, if ever, provides a direct lead to a wanted killer.
Between their vague nature and the lack of research supporting their validity, criminal
profiling has been criticized as a reckless misuse of police time and resources.
That doesn't mean you can't still enjoy Mindhunter, but you may have to work a little harder to
suspend your disbelief.
Never Changes
When dealing with serial murder, investigators pay close attention to the killer's M.O.,
or Modus Operandi.
In criminology, an M.O.
describes the method an offender uses to commit their crimes.
Identifying the M.O.
can be useful in solving multiple murders committed by the same person, but it would
be a mistake to assume a killer's M.O.
never changes.
According to FBI agent and behavioral analyst John Douglas, a serial murderer's M.O. should
be viewed as a work-in-progress that evolves the longer they're active.
He told Mental Floss in 2019: "When a criminal starts perpetrating crimes, if something doesn't
go right, he's got to perfect the M.O."
It's also a mistake to use M.O. and signature interchangeably.
While an M.O.
refers specifically to the murder method, a killer's signature is a ritual that isn't
necessary to commit the crime.
If a serial killer collects the same garment from each of their victims as a trophy, that
does nothing to aid them in their crime—in fact, it could make them easier to catch.
M.O. and signature are both important pieces of information in serial killer cases, and
understanding how they work and differ is vital to the investigators' success.
Consume enough true crime content and you’ll start to suspect that serial killers are lurking
around every corner.
The truth is that serial killers pose a much smaller threat to the average person than
our culture’s obsession with them would have you believe.
According to the FBI, serial killers are responsible for less than 1 percent of all murders in
the U.S.
Just 30 people fell victim to serial murderers in 2015.
The reality is that the 24,576 homicide victims who were murdered in the U.S. in 2020, for
example, were much more likely to be targeted by someone they know than a random person
who’s out for blood—but those cases don’t always make for exciting podcast fodder.
We’ve got an upcoming episode covering misconceptions about cryptocurrency.
Drop a notable myth about crypto in the comments for a chance to be featured in that episode.
I’m sure this will go... swimmingly. Thanks for watching!