The IQ of Serial Killers: Unraveling the Intellect behind Infamous Crimes

Let's take a moment to consider human intelligence. Perhaps the best way to assess it is through the intelligence quotient (IQ). Although it is not a perfect parameter for measuring cleverness, it at least provides a standardized method to test someone's level of intelligence.

The average person has an IQ ranging from 90 to 110, while according to "The Serial Killer Information Center," the IQ of a serial killer falls slightly below that at 94.5.

Of course, just like in the general population, there are variations among serial killers as well. But what can we learn from this? Is there a correlation between a killer's IQ and their crimes?

ABOVE AVERAGE

NATHAN LEOPOLD, IQ 210

When wealthy students Nathan Leopold and Richard Loeb kidnapped 14-year-old Bobby Franks in Chicago in 1924, they had no real motive, at least not a traditional one. When they beat him to death, disposed of his body in a ditch near railroad tracks outside the city, and acid-burned his face to make identification difficult, it wasn't for financial reasons or revenge. They simply wanted to test if they could get away with murder.

They had planned it for months. Although they never intended for the boy to survive, they sent his parents a ransom demand of $10,000. Before any exchange could take place, a railway employee discovered the victim's body much earlier than the duo had anticipated. Alongside the lifeless body, a specially made pair of glasses was found, leading investigators quickly to Leopold. During the interrogation, the friends confessed to their crime.

Leopold and Loeb were seeking thrills. Later, their story would serve as the basis for Alfred Hitchcock's film "Strangers on a Train." Both were exceptionally intelligent. Leopold completed college at the age of 19 and pursued a law degree, while Loeb became the youngest graduate of the University of Michigan.

However, their high IQ and their arrogant motive of wanting to commit the perfect crime did not save them from being sentenced to life imprisonment. To put Leopold's IQ of 210 into perspective: only 2% of the population has an IQ above 130.

TED KACZYNSKI, IQ 167

Technically classified more as a "domestic terrorist" than a serial killer, the Unabomber is still noteworthy due to his deadly crimes and high IQ.

CHARLENE GALLEGO, IQ 160

The actions of the couple known as "The Sex Slave Murders," Gerald and Charlene Gallego, were not driven by high moral principles, as one might imagine.

Charlene Gallego came from a well-to-do family, showed great musical talent, and performed well academically. However, at the age of twelve, she began using drugs and became alcohol-dependent by fourteen. Despite her high IQ, she barely managed to graduate from school.

After meeting and marrying Gerald Gallego, things took a turn for the worse. The duo kidnapped, raped, tortured, and murdered ten young women. While Gerald was sentenced to death multiple times, Charlene received a reduced sentence. Why? In exchange for testifying against her partner and providing details about the crimes, she was sentenced to only sixteen years and eight months. It was a clever move by a woman considered highly intelligent with an IQ of 160. She is now free, while her partner died of cancer before his death sentence could be carried out.

ANDREW CUNANAN, IQ 147

The murderer of Giovanni Versace and others, Andrew Cunanan, was a relatively unknown figure in criminal history for a long time. However, the TV series "American Crime Story" brought him into the spotlight, highlighting his manipulative and deceitful sociopathic nature.

EDMUND KEMPER, IQ 145

Kemper was tall, strong, and wild. He was also polite and continues to be a model prisoner. Edmund Kemper was many things, but above all, he was an enigma. His significantly high IQ undoubtedly helped him remain undetected during his killing spree.

JEFFREY DAHMER, IQ 145

Few of us would use the word "genius" to describe Jeffrey Dahmer. The "Milwaukee Cannibal" is one of the most infamous serial killers in history. However, his IQ tests indicated that he was indeed highly intelligent.

DR. HAROLD SHIPMAN, IQ 140

Doctors are generally above average in intelligence. The average physician scores around 120 on IQ tests, significantly higher than the general population. One cannot get away with murdering nearly 250 people without being clever in a peculiar way. However, while Shipman's IQ suggests that he was a genius, his actions indicate a heartless psychopath.

TED BUNDY, IQ 136

Ted Bundy was charming, good-looking, and intelligent. Let's not forget that he was also a brutal rapist and murderer of women.

JOHN WAYNE GACY, IQ 118

The "Killer Clown" ranks above average in the IQ scale. However, with at least 33 murders attributed to him, Gacy is definitely not someone we would call a genius.

DAVID BERKOWITZ, IQ 118

In a Who's Who of American serial killers, one name cannot be omitted: "Son of Sam" David Berkowitz. He senselessly shot and killed six people and seriously injured seven others.

With an IQ of 118, he falls above average.

AVERAGE

TOMMY LYN SELLS, IQ 100

"The Coast to Coast Killer" Tommy Lyn Sells, a violent burglar and murderer, scored exactly the U.S. average on the intelligence quotient when he was tested after his arrest.

EDWARD EDWARDS, IQ 108

Serial killer Edward Edwards primarily turned to crime for one reason: he wanted to become famous through his criminal acts. After escaping from prison in 1952 and committing multiple thefts while traveling across the United States, he achieved that goal. Edwards made it onto the FBI's Ten Most Wanted Fugitives list.

After being arrested, convicted, and released, he went on to kill at least five more people. He received the death penalty but died of natural causes shortly thereafter.

With an IQ of 108, his intelligence was above average.

RICHARD CHASE, IQ 95

The estimated intelligence of the "Vampire of Sacramento" can be considered normal, although his crimes were anything but. As a rapist, serial killer, necrophiliac, and cannibal, Chase is beyond madness. Before his murderous pursuits, he was an average student who graduated from high school without disciplinary problems.

BELOW AVERAGE

HENRY LEE LUCAS, IQ 85

While achieving low scores on IQ tests, being dyslexic and having ADHD, Henry Lee Lucas, at least in relation to his murderous partner Otis Toole, was the smarter one. He scored 11 points higher on the IQ test.

FRED WEST, IQ 84

Fred West, a high school dropout who worked as a laborer most of his life,

had severely limited intellectual capabilities. During police interrogations, an "appropriate adult" was appointed to assist him due to his low mental capacity.

His low intelligence might explain how easily his wife Rose, who is believed to have been the "brains" behind their gruesome acts, could manipulate him.

GARY RIDGWAY, IQ 82

The "Green River Killer," Gary Ridgway, killed between 50 and 70 women from 1982 to 2001. That's a full 20 years during which he could murder with impunity and elude capture by the police. However, with his below-average IQ, he was definitely not a criminal mastermind.

AILEEN WUORNOS, IQ 81

The IQ of Aileen Wuornos, the most notorious female serial killer in history, suggests low intelligence, although reality can differ. It is speculated that Wuornos did not take the test seriously and did not give her best effort.

JOACHIM KROLL, IQ 76

Joachim Kroll was a serial killer, serial rapist, and cannibal who terrorized the Duisburg area in the 1970s. He became known as the "Duisburg Man-Eater."

Kroll was considered intellectually challenged even as a child compared to his peers and attended special education, but he didn't complete it. An IQ test later revealed his score to be only 76.