There's been a huge spike in the production of zombie movies lately, and many of them seem to be inspired by war. Everything from 28 Days Later to Zombie Strippers make explicit reference to wartime, as did seminal 1968 zombie flick Night of the Living Dead. Is there really a connection between zombie movies and social unrest? We decided to do some research and find out. The result? We've got a line graph showing the number of zombie movies coming out in the West each year since 1910 — and there are definite spikes during certain years, which always seem to happen eerily close to historical events involving war or social upheaval.

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!

Send an email to Annalee Newitz, the author of this post, at annalee@io9.com.