I Come In Peace is pretty much an all-time classic, thanks to inserting an alien thug into the standard buddy-cop cliches. There are two cops, and they don't get along even though they both have unorthodox methods for cleaning up the streets. And then it turns out the main baddie is an alien, who's just the first of millions of alien endorphin-harvesting drug dealers — unless Dolph and his partner Brian Benben can stop him. There are fight scenes, shootouts and car chases, all of it to the tunes of Miami Vice's Jan Hammer. Really, what's not to like? [IMDB]

Psychology professor Jean Decety and his team analyzed the brains of bullies — teens who had showed unusual aggression, starting fights, using weapons, and mugging people. He put the bullies in a functional MRI scanner, looking to see how their brains reacted to pictures of a person deliberately stepping on someone else's foot. Said Decety:

Aggressive adolescents showed a specific and very strong activation of the amygdala and ventral striatum (an area that responds to feeling rewarded) when watching pain inflicted on others, which suggested that they enjoyed watching pain.

Earlier this year, Decety demonstrated that most children respond to these images of pain with sympathy, imaginatively feeling the pain themselves. And that's what the control group in his most recent study did. But the bullies clearly liked seeing pain.

Decety thinks his discovery will help psychologists and psychiatrists treat violent adolescents. He believes that when teens enjoy other people's pain it means they've suffered a disruption in their brains' natural empathetic reactions.

In other words, someday we might have a "cure" for aggression that restores bullies' ability to feel sympathy for other people's pain. Of course, tinkering with this brain signaling mechanism might also reveal a way to disrupt people's empathy too — turning pacifists into sadists.

Source: "Atypical Empathetic Responses in Adolescents with Aggressive Conduct Disorder: A functional MRI Investigation" [via Biological Psychology]

Mostly we've focused on movies from the U.S. and Europe, and we've included the living dead among zombies — so mummies are included, but vampires and ghosts aren't. Obviously as you look at this chart, you have to correct somewhat for the fact that more movies are being made as we get closer to the present, and (more importantly) there are better records of those movies with better tagging. So it's easier to research movies with zombies in them if you're looking at productions from the 1980s onward. In addition, there's been a huge boom in indie and low-budget horror movies over the past ten years, and that undoubtedly accounts somewhat for the giant spike you see during the last 8 years or so.

Still, even correcting for the fact that there are more movies being made today, you can see that there are distinctive spikes in zombie popularity - and they always seem to fall slightly after a huge political or social event has caused mass fear, chaos, or suffering. That's why World War II, Vietnam, and the current Iraq War are all followed by a zombie rush at theaters. Obviously, if you're going to look at these historical correlations, you have to consider that movies inspired by a real-life event aren't going to show up in theaters for at least six months to a year, so we've accounted for that.

You can see that most of these spikes in zombie popularity do seem weirdly close to periods of historical trauma like wars or the AIDS epidemic. Is there a causal connection, or is it just coincidence? You be the judge.

Chart by Stephanie Fox. Additional reporting by Katharine Duckett.

Appendix: Zombie movies we included in this study.

1910: 1
Frankenstein

1911: 1
The Mummy

1919
J’accuse!

1931: 1
Frankenstein

1932: 1
White Zombie

1933: 1
The Ghoul

1935: 2
The Lost City
Bride of Frankenstein

1936: 4
Revolt of the Zombies
Ouanga
Midnight Blunders
The Walking Dead

1938: 1
J’accuse! (Remake)

1939: 1
Son of Frankenstein

1940: 1
The Ghost Breakers

1941: 1
King of the Zombies

1942: 1
Bowery at Midnight

1943: 4
Dead Men Walk
I Walked With a Zombie
Revenge of the Zombies
Frankenstein meets the Wolf Man
The Mad Ghoul

1944: 1
Voodoo Man

1945: 1
Zombies on Broadway

1946: 1
Valley of the Zombies

1952: 1
Zombies of the Stratosphere

1953: 1
Scared Stiff

1955: 1
Creature with the Atom Bain

1957: 3
The Zombies of Mora Tau
Voodoo Island
The Unearthly

1958: 4
Womaneater
The Revenge of Frankenstein
The Brain Eaters
Misterios de la magia negra (Mysteries of Black Magic)

1959: 6
Invisible Invaders
Teenage Zombies
The Mummy
Plan 9 From Outer Space
The Four Skulls of Jonathan Drake
Night of the Ghouls

1960: 1
Creature of the Walking Dead

1961: 3
Muñecos infernales (The Curse of the Doll People)
The Dead One
Dr. Blood’s Coffin

1962: 2
Carnival of Souls
Santo contra los zombies (Invasion of the Zombies)

1963: 1
They Saved Hitler’s Brain

1964: 7
Roma contro Roma (War of the Zombies)
The Curse of the Living Corpse
El Secreto del Dr. Orloff (The Secret of Dr. Orloff)
The Last Man on Earth
Monstrosity
Zombies
The Incredibly Strange Creatures Who Stopped Living and Became Mixed-up Zombies
Der chef wünscht keine Zeugun (No Survivors, Please)

1965: 2
Earth Dies Screaming
Terrore nello spazio (Planet of the Vampires)
Cinque tombe per un medium (Terror Creatures from the Grave)

1966: 2
The Plague of the Zombies
The Death Curse of Tartu

1967: 2
They Came From Beyond Space
Dr. Terror’s Gallery of Horrors

1968: 6
Night of the Living Dead
Dr. Satán y la magia negra (Dr. Satan Versus Black Magic)
The Wild Wild West: Night of the Undead
Astro-Zombies
Blue Demon contra cerebros infernales (Blue Demon vs. El Crimen)
Autopsia de un fantasma (Autopsy of a Ghost)

1969: 2
Frankenstein Must Be Destroyed

1970: 4
Night Slaves
Dream No Evil
El mundo de los muertes (Land of the Dead)
Santo el enmascarado de plata y Blue Demon contra los monstrous (Santo and Blue Demon Against the Monsters)

1971: 4
La muerte viviente (Island of the Snake People)
La noche del terror ciego (Tombs of the Blind Dead)
Escape
The Resurrection of Zachary Wheeler

1972: 7
Gli orrori del castello di Norimberga (The Torture Chamber of Baron Blood)
L’Etrusco uccide ancora (The Dead Are Alive)
La Notte dei diavoli (Night of the Devils)
Blood of Ghastly Horror
Children Shouldn’t Play With Dead Things
Tales From the Crypt
(Las momias de Guanajuato) The Mummies of Guanajuato

1973: 15
El espanto surge de la tumba (Horror Rises From the Tomb)
La invasión de los muertos (Invasion of the Dead)
La orgía de los muertos (Beyond the Living Dead)
El ataque de los muertos sin ojos (Attack of the Blind Dead)
Christina, princesse de l'érotisme (A Virgin Among the Living Dead)
El castillo de las momias de Guanajuato (Castle of the Mummies of Guanajuato)
Horror Express
Dead People
La noche de los brujos (Night of the Sorcerors)
La rebelión de las muertas (Vengeance of the Zombies)
Psychomania
Flesh for Frankenstein
Santo contra la magia negra (Santo vs. Black Magic Woman)
House of the Living Dead
Vudú sangriento (Voodoo Black Exorcist)

1974: 13
Dead of Night (Deathdream)
Garden of the Dead
Corpse Eaters
House of Seven Corpses
House on Skull Mountain
Legend of the 7 Golden Vampires
Non si deve profanare il sonno dei morti (Let Sleeping Corpses Lie)
Shanks
Sugar Hill
El buque mandito (Horror of the Zombies)
El pantano de los cuervos (Swamp of the Ravens)
Young Frankenstein
Kung bakit dugo ang kulay ng gabi (Night of the Zombies)

1975: 7
Macchie Solari (Autopsy)
The Dead Don’t Die
Frozen Scream
La noche de las gaviotas (Night of the Death Cult)
Lord Shango
Shivers
La Perversa caricia de Sátan (The Wicked Caresses of Satan)

1976: 1
Gou hun jiang tou (Black Magic II)

1977: 3
The Child
Shock Waves
La fille á la fourrure (The Porno Zombies)

1978: 4
Dawn of the Dead
Les raisins de la mort (Grapes of Death)
Salinnabileul ggotneun yeoja (Living Dead Girl)
Within the Woods

1979: 4
Zombi 2
Io Zombo, Tu Zombi, Lei Zomba (I Am a Zombie, You Are A Zombie, She Is A Zombie)
Phantasm
The Day It Came to Earth

1980: 10
Zombi Holocaust
John Carpenter’s The Fog
Alien Dead
The Children
Bloodeaters
Paura nella città dei morti viventi (City of the Living Dead)
Fiend
Virus
Incubo sulla città contaminata (City of the Walking Dead)
Más allá del terror (Further Than Fear)

1981: 13
Night of the Zombies
L’aldilá e tu vivtai nel terrore (The Beyond)
Heavy Metal
Quella villa accanto al cimitero (The House Outside the Cemetery)
Le notti del terrore (Burial Ground)
Dawn of the Mummy
Dead & Buried
Le Lac des morts vivant (Zombie Lake)
Frankenstein Island
L’abîme des morts vivants (Bloodsucking Nazi Zombies)
Kiss Daddy Goodbye
Evil Dead
Rosso Sangue (Absurd)

1982: 9
Aftermath
Creepshow
Raw Force
I was a Zombie for the F.B.I.
Wu long tian shi zhao ji gui (Kung Fu Zombie)
O segredo da Múmia (The Secret of the Mummy)
Pengabdi setan (Satan’s Slave)
The Curse of the Screaming Dead
Revenge in the House of Usher

1983: 5
Frightmare
Natas: The Reflection
One Dark Night
Sole Survivor
Zeder

1984: 6
Surf II
Night Shadows
Night of the Comet
Zombie Island Massacre
Frankenstein 90
Rocktober Blood

1985: 12
Hard Rock Zombies
Return of the Living Dead
Re-Animator
The Midnight Hour
The Dark Power
Attack of the Beast Creatures
Dead End
La mansión de los muertos vivantes (Mansion of the Living Dead)
Day of the Dead
Lifeforce
Warning Sign
Cementerio del terror (Zombie Apocalypse)

1986: 12
Zombie Brigade
Zombiethon
The Supernaturals
Loves of the Living Dead
Diamond Ninja Force
Deadly Friend
Nightmare Weekend
Goremet: Zombie Chef From Hell
Night of the Creeps
Raiders of the Living Dead
Zombie Nightmare
Abracadabra

1987: 14
Bad Taste
Evil Dead 2
I Was a Teenage Zombie
Dak Bangla
The Gate
Zombie 5: Killing Birds
Redneck Zombies
Killing Spree
La revanche des mortes vivantes (Revenge of the Living Dead Girls)
Zombie High
Video Dead
Zombie Vs. Ninja
Night of the Living Babes
Una notte al cimitero (Graveyard Disturbance)

1988: 11
The Serpent and the Rainbow
Return of the Living Dead Part II
Dead Heat
Waxwork
Phantasm II
Zombi 3
FleshEater
Zombie 4
Pet Semetary
Meng gui xue tang (The Haunted Cop Shop II)
Curse of the Blue Lights

1989: 17
The Laughing Dead
The Dead Next Door
The Vineyard
Curse of the Zombie
Beverly Hills Bodysnatchers
The Chilling
The Dead Pit
Blood Nasty
Zombie Rampage
Hellgate
Zombie Party
Working Stiffs
The Nutzoids at Cannibal Cove
From the Dead of Night
Ginseng King
Monster High
Night Life

1990: 5
Bride of Re-Animator
Night of the Living Dead
Voodoo Dawn
Demon Wind
Linnea Quigley’s Horror Workout

1991: 9
Chopper Chicks in Zombietown
The Boneyard
Demoni 3
Nudist Colony of the Dead
Teenage Exorcist
Zombie ja Kummitusjuna (Zombie and the Ghost Train)
Zombie Army
Zombie Cop
Zombie ’90: Extreme Pestilence

1992: 11
Brain Dead
Batoru garu (Battle Girl)
Netherworld
Waxwork II
Zombie Rampage 3
Pet Semetary II
Death Becomes Her
Army of Darkness
Urban Scumbags vs. Countryside Zombies
Dead is Dead
Zombie Rampage 2

1993: 7
My Boyfriend’s Back
Return of the Living Dead 3
Zombie Bloodbath
Space Zombie Bingo!!!
The Killing Box
Zombie Genocide
Drag

1994: 7
Mary Shelley’s Frankenstein
Shatter Dead
Shrunken Heads
Phantasm III: Lord of the Dead
Twilight Zone: Rod Serling's Lost Classics
Dellamore Dellamore
Gore Whore

1995: 6
La Cage aux Zombies
Legion of the Night
Zombi I
Zombie Bloodbath 2: Rage of the Undead
Voodoo
Zombie Holocaust

1996: 4
Living a Zombie Dream
Zombi vs. Mardi Gras
Avaruuden teurastajat (Space Butchers)
Frankenstein and Me

1997: 10
Plaga Zombie
Premutos: Lord of the Living Dead
Uncle Sam
The Necro Files
Night of the Living
Le Zombi de Cap-Rouge
Zombie Ninja Gangbusters
Striker Bob
Bryllupsnatten (The Wedding Night)
The Viscious Sweet

1998: 9
Bio Zombie
I, Zombie: A Chronicle of Pain
Zombie Cult Massacre
Laughing Dead
Tale of the Mummy
Into the Woods…
The Cabin
Hollywood Mortuary
Zombie Toxin

1999: 5
Hot Wax Zombies On Wheels
The Mummy
VS3: Infantry of Doom
Mutation
The Collegians Are Go!!

2000: 12
The Dead Hate the Living!
Flesh Freaks
Junk: Shiryô-gari
Meat Market
Prison of the Dead
Versus
Wild Zero
Zombie Bloodbath 3: Zombie Armageddon
Teenage Zombie House Massacre
Reign of the Dead
Heavy Metal 2000
The Horrible Dr. Bones

2001: 15
Cremains
Mulva: Zombie Ass-Kicker!
Biohazardous
Dead in America
Stacy
Meat Market 2
Zombie (zero)
Biker Zombies
Children of the Living Dead
Plaga Zombie: Zona Mutants
The Mummy Returns
Zombie Chronicles
Night of a Thousand Screams
R.I.P.
The Resurrection Game

2002: 9
Bubba Ho-Tep
Deadline
Cremaster 3
Mark of the Astro-Zombies
Necropolis Awakened
Resident Evil
Zombie Campout
Roni vs. Lincoln
Evil Night
28 Days Later…

2003: 22
House of the Dead
Beyond Re-Animator
Cadaver Bay
Flesh For the Beast
Maplewoods
Mummy’s Kiss
Xombie: Dead on Arrival
Undead
Graveyard
Corpses Are Forever
Noctem
Zombie Beach Party
I’ll See You in My Dreams
Gory Gory Hallelujah
Zombiegeddon
Night of A Thousand Screams 2
Necro Files 2
Zombie Night
Exhumed
Wiseguys vs. Zombies
The Mental Dead

2004: 29
Jigoku kôshien (Battlefield Baseball)
Dawn of the Dead
Dead and Breakfast
Shaun of the Dead
Choking Hazard
Les Revenants
Resident Evil: Apocalypse
Vampires vs. Zombies
Beaster
Zombie Vegetarians
Dawn of the Friend
Corpses
Angry and Moist: An Undead Chronicle
Bad Friend
Bone Sickness
Curse of the Maya
Dead & Breakfast
Feeding the Masses
Ghost Lake
Hide and Creep
Hunting Creatures
Night of the Living Dorks
Rotten Shaolin Zombies
Khun krabii hiiroh (SARS Wars)
Shadows of the Dead
Shao Lin jiang shi (Shaolin Vs. Evil Dead)
Zombie Honeymoon
Zombie Nation
Zombie Planet

2005: 29
Day of the Dead 2: Contagium
Land of the Dead
The Wickeds
Zombiez
Boy Eats Girl
Bubba’s Chili Parlor
Day X
Dead at the Box Office
Dead Creek
Dead Life
Dead Men Walking
Die You Zombie Bastards!
Die Zombiejäger
Le divan vert
Doom
Hood of the Living Dead
House of the Dead 2
Livelihood
Living Dead Lock Up
Pot Zombies
Raiders of the Damned
Return of the Living Dead 4: Necropolis
Return of the Living Dead 5: Rave to the Grave
Rise of the Undead
The Roost
Severed
The Stink of Flesh
Swamp Zombies
(Tôkyô zonbi) Tokyo Zombie

2006: 34
After Sundown
Awaken the Dead
Automaton Transfusion
Awakening
City of Rott
Dead & Deader
Dead in the Water
The Dead Live
Deadlands: The Rising
Die and Let Live
Doomed to Consume
Dorm of the Dead
Electric Zombies
Enter the Zombie
Fido
Gangs of the Dead
L’isola dei morti viventi (Island of the Living Dead)
Last Rites of the Dead
Meat Market 3
Mortuary
Night of the Dead: Leben Tod
Night of the Living Dead 3-D
The Plague
The Quick and the Undead
Shadow: Dead Riot
The Slaughter
Slither
Special Dead
Storm of the Dead
Stoned Dead
War of the Dead
Wicked Little Things
The Zombie Diaries
Zombies by Design

2007: 33
28 Weeks Later
American Zombie
Awaken the Dead
Beneath the Surface
Brain Blockers
Days of Darkness
Dead Heist
Dead Moon Rising
The Dead Undead
Evil Keg
Flight of the Living Dead: Outbreak on a Plane
Forest of the Dead
Forever Dead
Living Dead Lock Up 2: March of the Dead
The Mad
Motocross Zombies from Hell
Mutation-Annihilation
Otto; or Up With Dead People
Planet Terror
The Rage
REC
Resident Evil: Extinction
Risen
Street Team Massacre
Undead or Alive
Undead Ted
Wasting Away
Z: A Zombie Musical
Zibahkhana-Hell’s Ground
Zombie Farm
Zombie Town
Zombies Gone Wild
Zombi: La creazione (Zombies: The Beginning)

2008: 9
Quarantine
Day of the Dead
Diary of the Dead
Outpost
Sabbath
Retardead
House of the Damned
Zombie Strippers
Zombies! Zombies! Zombies!

For every 1,000 litres of alcohol sold in stores (there were no stats for what got sold in bars), numbers of violent assaults and deaths nearby increased by 13%. For young people, the risk increased by 21%. One could easily imagine a dystopian future where cities zone certain "undesirable" areas for more liquor stores, as a way of trimming down or crippling the population there.

What's particularly interesting about this study is how the researchers got their data. The Canadian province Ontario does an very accurate job of tracking alcohol sales in stores (not bars) because the government regulates stores that sell liquor. In addition, hospitals in the province keep highly-accurate records of assaults. So the region was basically a goldmine for data about how alcohol sales might impact assaults.

Alcohol Sales and Risk of Assault [PLoS Medicine]

I still use this little survival mechanism to get through the scary scenes in movies. It's amazing how covering your ears, rather than your eyes, makes it all much more bearable. Plus, I wouldn't want to miss the best parts: the spatter of gore when the infected lady explodes; the crunch of the monster's gigantic mouth through the annoying dude's neck; the boiling pool of bloodslime where the ladies stab each other with rock-climbing equipment while a monster looks on; the giant alien orgy where some poor sucker gets dissolved and eaten.

So I have trained myself to watch horror movies, using little tools like fingers-in-the-ears and watching so many flicks in the genre that I know what will happen before the director does. And I'm willing to admit that I pay a little price in my electricity bills every month. That's right: I can't sleep without leaving the hall light on. I've got too many excellent eviscerations packed into my imagination to ever sleep soundly again.

Why do I do it? Why do we all do it? Here are five reasons — they may not be good reasons, but I guarantee that they are true.

To Survive
As I have already pointed out with my little story about Invasion of the Body Snatchers, part of the fun of every horror flick is getting through it alive. I am a firm believer that the right way to watch horror is not to distance yourself from it, but to plunge in and let yourself be completely credulous and scared. Sure the monster in Neil Marshall's amazing spelunking horror flick The Descent was a little cheesy, but watching those women get deeper and deeper into the dark tunnels, more and more lost, squeezing through the claustrophobic, dirty spaces and into madness — if you let yourself feel the horror of the situation, you'll be thrummingly high on relief when the flick ends.

To Take Your Secret Thoughts to Their Most Extreme — and Laugh
When I first saw Stuart Gordon's mad doctor gorefest Re-Animator, it was like a revelation. There were all these gross brain-operation scenes, and headless zombies, and people drooling blood. And that was good, but I'd been over that terrain before. But then came the moment of pure breakout genius. The headless zombie bad guy, whose body carries his head around in a bowling bag, finally kidnaps the lady he's been wanting to hook up with. His body straps the lady to a medical table, and proceeds to jam his severed head between her wiggling legs. He's giving her head! Also, holy crap what the fuck. Director Gordon WENT THERE. I mean, he wasn't afraid to just show you the most fucked up thing he could possibly imagine. How could even your weirdest private thoughts ever seem disturbing once you've laughed at the most fucked-up thing in the universe? Same goes for the moment in Frank Henenlotter's Brain Damage where the main character's penis-shaped parasite hides in his jeans and pops out to eat the brains of a girl who is just trying to give him a nice blowjob. Damn. I will never feel weird about any of my random fantasies ever again, because they can't top what Henenlotter actually committed to film.

To Let Everyone in on Your Nightmares
All of us have dark thoughts, but probably some of us more than others. I'm one of the ones with the ultra-super-dark thoughts — and my dreams are even worse. But the whole situation becomes a hell of a lot more bearable, and even fun, when some of those dark thoughts are realized in film. After all, most of our dark thoughts aren't really unique or special. That's why I will always treasure David Cronenberg's mad gynecologist movie Dead Ringers. Those gynecological tools for mutant women, pictured below? Oh yeah, I imagined stuff like that about twenty million times before I saw them in his flick. And now I can force all my friends to think about them with me when we watch the movie together. Same goes for the lady impregnated by aliens in Slither, who grows to the size of a barn before exploding with all those sperm-shaped baby aliens going everywhere. Sick, but I've dreamed that one too. Welcome to my mind. Nice to have company in here!

To Speak the Unspeakable
It may be hard to articulate what's wrong with your city, your sexuality, or your relationship with your boss. That's why horror does it for you, in grisly, unsparing detail. While the movie Akira is usually billed as pure scifi, anybody who has watched the grotesque physical mutation-explosion of the gangster-psychic Tetsuo at the end knows that it's also a terrifying look at the unspoken but well-known psychological consequences of poverty in the city. And anyone who has ever quietly suspected her boss might be controlling the fabric of reality was rewarded by that scene in The Matrix when Neo is kidnapped by Agent Smith, told to be a good little worker, and then tortured and implanted with a tiny robot while his mouth is sewn shut. In a few months, when Frank Henenlotter's latest movie Bad Biology hits theaters, we're about to get a good dose of inexpressible sexual panic in a tale of a guy whose giant cock is both detachable and addicted to drugs — so it's always running away to score some dope. I know the feeling. But I wouldn't have been able to tell you about it without the help of Henenlotter's film.

To Shove a Big Spiny Stick Up Rationality's Ass
The great part about science horror, full of mad doctors doping themselves with Hyde serum and physics experiments gone wrong, is that they are a slap in the face to so-called rationality. How many times have you heard someone describe the "rational thing to do" and known that it was also the worst, scariest thing to do? Sure, it was "rational" to try to get samples of those aliens in the first Alien flick; and it was "rational" to put that futuristic Prozac in the air of that planet in Serenity that created the rapin, cannibalizin' Reavers; and it was rational to genetically engineer dinosaurs for a cool new theme park in Jurassic Park. All those things were done with pure science in mind (and a little profit). My point? Scientific rationality is great and all, but scifi horror is here to remind you suckas that sometimes you need to check with your ethics and all that mushy crap before experimenting on people's brains or messing around with outer-space superweapons that you don't understand. Your science won't save you when the Hulk comes around to beat your sorry ass.