With Halloween night only hours away, it’s time to examine the IQ’s of various slashers (someone else on the internet has made similar attempt). Not every character I’m examining is a slasher, strictly defined, but they’re all close enough.

Leatherface from the Texas Chainsaw movies: IQ 46

Leatherface is too stupid to talk but he does squeal like a pig. Not being able to talk indicates a mental age of less than one year, and since Leatherface is an adult, and since mental development peaks around age 16, Leatherface is verbally functioning at a level no more than 6% of normal cognitive development (1/16) or a verbal ratio IQ 6.

His nonverbal IQ is much higher though because he can operate a chainsaw and even run after people with it. He also has the spatial motor skills needed to remove people’s faces and sew them to his own. This probably indicates a mental age of at least 10, though not much more than that since Leatherface has had years of practice perfecting these skills, and unlike his family, is never once seen driving a vehicle, suggesting limited ability. A mental age of 10 implies a non-verbal ratio IQ of 63. Averaging this with his verbal ratio IQ of 6 gives an overall ratio IQ of 35. However it’s well known that ratio IQ’s give extreme results, and thus psychologists now use deviation IQ’s, so a ratio IQ of 35 is like a deviation IQ of 46.

Most fans of the Texas Chainsaw movies know that Leatherface is mentally disabled. Less known is that his whole family might be also according to film critic Roger Ebert who described them as a “a demented family of retarded murderers and grave robbers”. Since the correlation between adult IQ and first degree relatives is about 0.5, we’d expect the relatives of Leatherface to regress halfway from Leatherface’s IQ of 46 to the mean of psychotic killers (IQ 76). This suggests Leatherface’s family would average IQ 61, so Roger Ebert was correct to imply the whole family is mentally retarded, though an IQ in the 60s back in those days was defined as educable (mild) retardation, while Leatherface’s IQ of 46 was classified as as trainable (moderate) retardation, so that’s why Leatherface stands out as conspicuously disabled and the family he relies on to give him orders seems so much smarter (though one relative stupidly gets hit by a truck in this scene)

Jason from the Friday the 13th movies: IQ 50

In the very first Friday the 13th movie (1980) (one of the best horror films ever) it was very subtly hinted by his mother that Jason was a special needs child when she used the euphimism “he wasn’t a very good swimmer”, and indeed the makeup artist who created Jason’s appearance described him as “hydrocephalic, mongoloid pinhead”. In Friday the 13th part 2, the main character mentions that Jason never went to school as a child. According to IQ expert Arthur Jensen, the minimum IQ needed to attend a regular school was 50 though Jason can’t be much lower than that because he manages to survive on his own in the woods from age the age of 11 to 34 and at age 34, kill a platoon of teenagers using a wide variety of weapons.

But Jason’s low IQ is revealed by his extreme gullibility. In Friday the 13th part 2, a college psychology major manages to trick Jason into thinking she is Jason’s mother simply by putting on his mother’s sweater, even though Jason personally witnessed his mother being beheaded and the college girl is more than a decade younger than Jason and thus can’t be his mother. In Friday the 13th part 4, Jason is tricked by a little boy who shaves his head and pretends to be young Jason himself, only to hack Jason to death. The fact that Jason was outsmarted and killed by a little kid half his size shows Jason was not too bright. Despite being killed at age 34 (short life span is another sign of low IQ, though a weak one) Jason returned in part 6 as a zombie.

Michael Myers from Rob Zombie’s Halloween remakes: IQ 80

Schizophrenic mental patient from Rob Zombie's 2007 remake of Halloween

Schizophrenic mental patient from Rob Zombie’s 2007 remake of Halloween

Because he was sent off to a mental hospital at age 10 in Rob Zombie’s Halloween remakes, Michael Myers probably has only a fourth grade education. Adults with only fourth grade education probably average IQ’s of 68. However in the Halloween remakes, Michael Myer’s grows up to be ridiculously tall (about 6’8″). Since height is weakly but positively correlated with IQ, we would statistically expect someone that incredibly tall to be significantly brighter than the average fourth grade dropout, hence an IQ around 80. For more information about this character’s IQ, see here.

Michael Myers from the original Halloween series: IQ 92


The original Michael Myers was sent to a mental hospital at age six and thus has only a kindergarten education. Statistically we should expect the average Americans with no formal education at all to average IQ 54, but the original Myers is likely a lot brighter than this. For one thing, unlike a lot of slashers, the original Myers can drive a car, despite spending his childhood and adolescence locked up. In addition his main victim and biological sister Laurie (played by Jamie Lee Curtis) probably has an IQ of 130, since she out-survives dozens of people and is a virgin because boys think she’s too smart to date. I would estimate the original Myers to have an IQ half-way between his sister Laurie (IQ 130) and the average IQ of first grade dropouts (IQ 54) so IQ 92 (typical of serial killers).

Billy from the original Silent Night Deadly Night: IQ 95

As a child Billy seemed like a bright boy who would have probably grown up to be a college graduate (average IQ 113), but he instead grew up to be criminally insane (average IQ 76) slasher. Let’s split the difference and assume his IQ is 95. Indeed some of the characters in the film state, he may be crazy, but he’s not stupid. But Billy’s psychosis is understandable when you consider that he witnessed his mother being raped and killed by a man dressed as Santa (who also killed Billy’s dad) and then was raised in an orphanage by a nun who mercilessly beat him if he said or did anything even remotely “naughty”. Perhaps this is one of those extreme cases where social environment matters and Billy’s later criminal insanity can not be blamed on defective biology. On the other hand, Billy’s grandfather is clearly demented too, so Billy likely inherited bad genes.

In the sequel, Billy’s younger brother Ricky takes over as the killer, further suggesting a genetic basis. Ricky is just a shorter stockier version of Billy, and since weight/height ratio is negatively correlated with IQ, I’d expect Ricky’s IQ to be somewhat lower (IQ 87), and indeed the scrawny guys in the neighborhood assume that Ricky is dumb. Here’s one of Ricky’s most popular kills:

The guy in The Strangers: IQ 120

The Strangers (2008) is one of the scariest movies I have ever seen, in part because we know so little about the killers, making their IQ’s especially hard to assess. All we know is that the killers are some guy and two girls who get off on terrorizing and killing a random upper class couple who are spending the evening in an isolated home. The male killer could be the father of the two female killers or he could be some high school kid and the two girls are his friends. Nothing is explained. The killers appear to have no understandable motive. When asked by one of the victims why they are doing this, one girl replies “because you were home”.

Maybe I’m being sexist but I assume the guy in the movie is the leader and I estimate his IQ to be 120; somewhat higher than the average crime leader. He and his two female sidekicks are smart enough to outsmart their upper-class (presumably university educated) victims all night, despite the fact the victims have a gun and the killers don’t.