You think you're riddled with anxiety, fear and a general sense of dread, Mr. or Ms. Modern American? Consider what it was like living in prehistoric times.

"You were completely a dead duck," says Wes Craven, famous director of horror films. "People got into crevices or climbed trees because any venomous creature or things with fangs and claws could get them in the middle of the night."

Makes your fear of public speaking seem a bit silly, doesn't it?

"I'm sure the first humans dreaded the dark and were very happy when they invented fire," Craven says.

As we head into another Halloween filled with purposely frightening imagery, we wondered: What really scares us? Millions of people may watch zombies on TV and in movies, but that's manufactured fear. We don't really worry about encountering the undead in our day-to-day activities. At the same time, our modern world is generally described as becoming increasingly frightening, with terrorism, disasters and deadly diseases regularly in the news.

"Fear is a good thing, to a certain extent," says David Tolin, author of Face Your Fears and director of the Anxiety Disorders Center at the Institute of Living in Hartford, Conn. "Without fear, we wouldn't be alive. Fear allows us to escape and avoid threat. The problem is that sometimes there is no threat."

That's where you get into anxiety disorders, which affect more than a quarter of Americans, Tolin says. "The solution is facing the thing we're afraid of. ... However, we have to be willing to accept a certain amount of fear in order to beat that fear."

Research is also helpful. "People tend to fear what they don't know," says David Borgenicht, co-author of more than a dozen books in the Worst-Case Scenario series. "If they have a stay-at-home lifestyle, they may fear flying, yet they're much more likely to be injured crossing the street. If they live in an urban environment, they may fear animal attacks.

RELATED: Survey: Top 5 Biggest Personal Fears

"Once you fortify yourself with knowledge or find yourself in the situation, your fears aren't so scary. … Snakes look and sound scary, but most are not to be feared — even though we've seen movies like Indiana Jones and Anaconda. It's pop culture having its way with us."

Borgenicht helps with his books. "People have told me they've been in situations we've described, and they knew what to do. One wrote that he remembered how to break down a door, and he saved his girlfriend from an apartment fire. My favorite scenario is what to do if you're stuck in an elevator and it starts to plummet. People think the correct thing is to jump before you hit bottom, but the place to be is down on the (floor), bracing yourself."

Borgenicht, 45, says he started confronting his own fears as a child in Utah, when he worried that burglars would break into his family's home at night.

"That fear inspired me to come up with all sorts of solutions. I kept a baseball bat and a tennis racket ready and practiced defending myself on my pillow."

Now well-versed in keeping cool under pressure, the author admits to some irrational fears: "Ventriloquist dolls creep me out."

Tolin acknowledges that he isn't always the picture of bravery, either. "I can run a little socially anxious. I don't mingle well at parties, but it doesn't prevent me from doing what I have to do. If it were more severe, I might not want to interact with people."

If the ultimate goal is to be afraid only of real threats — experiencing the good fear that protects us rather than the bad fear that limits us — then why do Americans by the millions seek out horror movies? Why do we want to be scared on purpose?

Craven, who directed the classics The Last House on the Left, The Hills Have Eyes, A Nightmare on Elm Street and Scream, says movies are another form of therapy. "For many years, I was appalled by what I'd done. Now I see things differently. People come up to me and say, 'You scared the heck out of me,' and then they pump my hand. I realized they were saying, 'Thank you for dealing with fears I have and letting me come to grips with them.'

"I show them what they're dealing with and how to confront it without dying."

As for Craven's own fears? As a kid, it was his father. Now it's "ISIS cutting off people's heads and climate change."

But not horror movies. "Freddy doesn't pop up in my dreams. He's a pal."

THIS! -- WFMY News 2: Halloween Fun Guide

FEARS THROUGH THE YEARS

1940s-1960s: "People were afraid of communism, and that continued through the Vietnam War," Craven says. "Communism was going to take over Asia, and (we thought) our goose is cooked. Now we go on vacation there."

1960s: "There was a lot of fear of government, lots of conspiracy theories after the John F. Kennedy assassination," Borgenicht says. "People distrusted their leaders."

1970s-1980s: "We feared the Cold War and the energy crisis," Borgenicht says. "Corporations, media and the government were pretty effective in keeping us in line with things we had no control over. There was a lot of cultural angst. Horror movies and zombie movies became popular."

1990s: "There was no outside enemy to fear," Borgenicht says, "so people began fearing each other."

2000s: "Our biggest fears are terrorism, Ebola and viruses," Borgenicht says, "but we're more likely to slip in the bathtub or eat too many french fries than die of the things most of us fear."

The future: "With technology and the convergence of the real world and the digital world, there are still plenty of new things to fear," Borgenicht says.

FEARS OF THE FAMOUS

"When my mother, brother and I moved from England to Australia (more than 30 years ago), we stopped in Bali. We went swimming and got caught in a riptide. I've since had a horrific fear of waves." — Naomi Watts

"When I started fronting (Detroit-based band) Chapter 8, I would stand so deep into the stage that the drummer would poke me in the back with his drumsticks. ... Every time I go on stage, I'm scared to death." —Anita Baker

"Snakes scare me. An episode of Stalker involves a lot of snakes, and I said, 'They better not be in a scene I'm in because I would not be able to show up.'" —Maggie Q

"I grew up in a tiny village in Denmark. Because the cemetery wasn't very big and it always seemed to be filled up, my friends and I had this theory that at night they'd empty out some graves to make room for new ones. In the back, all these ghosts were lurking around. We were convinced that was the truth, and that fear of ghosts has never left me." — Nikolaj Coster-Waldau, Game of Thrones

"No animal gives me the creeps, but the scariest animals are humans. They don't telegraph their emotions as some wild animals do. Human beings might not tell you they're annoyed, and then they wheel around and attack you."—Dominic Monaghan, Lost