20 Childhood Fears That Stick with You Until Adulthood

An estimated 15 million American adults suffer from some sort of phobia, according to the National Institute of Mental Health (NIMH). Though these phobias differ in type and severity, most of them have one thing in common: They developed in adolescence.

Just as our childhood shapes our personality, it's also likely to determine our greatest fears. And while some of us might have been fortunate enough to have left our deepest dreads in the past—along with potty training and pacifiers—the rest of us are stuck with a crippling fear of everything from crowded spaces to cuddly canines. Curious what some of the most common childhood-turned-adult fears are? Read on, and for more fascinating knowledge, read up on these 50 Mind-Blowing Horoscope Facts.

It's no secret that most kids prefer a nightlight in his or her room. But nyctophobia—that's fear of the dark for the uninitiated—is a pervasive and irrational fear that sticks with people long after maturation. In fact, according to John Mayer, Ph.D., 11 percent of Americans are unable to score restful sleep in a pitch-black room.

Our fear of clowns likely developed during childhood, but that doesn't mean that it stayed there. According to a Vox poll of nearly 2,000 Americans, adults are more afraid of the unsavory performers than they are of global warming. Maybe we all just need to stop watching so much American Horror Story.

Roughly one in 15 people suffer from acrophobia, or a fear of heights, at some point in their lives. For some, this phobia is manageable so long as glass elevators and steep hikes are avoided; for others, even something as minimal as climbing a steep staircase becomes an arduous and traumatizing task. And if you're looking for a way to conquer an even more common fear, here's The Single Best Way to Be a Better Public Speaker.

A fear of strangers, crippling social anxiety—whatever you want to call it—can affect your life well past adolescence. As a child, getting nervous around new people was cute and endearing; now, it just makes it nearly impossible to function. If you find yourself uncomfortable in social situations, try these 12 Genius Tricks for Turning Anxiety into Excitement.

As a child, nothing induces more fear than the mere thought of being left alone without a responsible adult in sight. But for some full-fledged adults, this worry persists beyond the younger years and morphs into autophobia, or the fear of feeling isolated and being ignored. Just look at the numbers: One survey found that over one in three adults fear being on their own.

In one survey conducted by Dogs Trust, 37 percent of parents in the United Kingdom said that their children were afraid of dogs. And unfortunately, cynophobia is just as common in adults as it is in children. If this sounds like you, perhaps we can help. Just see these 25 Photos Proving Dogs Are the Best Co-Workers.

Trypanophobia, or a fear of needles, affects more than just your mind. For people with the aversion, seeing a needle incites a vasovagal response in which their heart rate and blood pressure quicken and subsequently drop. In other words: They pass out.ae0fcc31ae342fd3a1346ebb1f342fcb

In the United States, the odds of getting struck by lightning in any given year are about one in 700,000. (To put that in perspective, your odds of being killed by fireworks are 1 in 340,733.) And yet, an estimated 75 percent of people grapple with some degree of fear toward the electrostatic discharge.

From children to adults to dogs, living beings of all shapes and sizes are scared of this intimidating natural element, so there's nothing to be ashamed of if the threatening roars of thunder have you hiding under your desk for cover.

According to the American Psychiatric Association, up to 40 percent of all phobias are related to bugs, mice, snakes, or bats. And arachnophobia—or a fear of spiders—plagues people more than the fear of losing their jobs, according to research from Chapman University. Basically, we're hardwired to really, really hate creepy, crawly creatures.

Despite the fact the overwhelming statistics that suggest it's an incredibly safe way to travel, many intelligent and rational people suffer from a fear of flying—or aviophobia. It's so common, in fact, that British Airways offers courses worldwide on how to overcome your fear of the sky, taught by some of the airline's pilots in conjunction with a licensed psychologist. And when you've conquered your fear, you'll be ready to know the 10 Worst U.S. Airports for Summer Travel.

Indiana Jones isn't the only one who hates snakes. According to a poll conducted by YouGov, 64 percent of Americans are afraid of snakes, and older Americans proved to be more fearful than their younger counterparts. Unsurprisingly, a German study showed that this fear comes naturally at a young age; when infants were shown pictures of scaly slithering snakes, their pupils dilated to indicate elevated levels of stress and anxiety.

Developing a fear of failure at any early age can have detrimental effects on our learning habits well into our adult lives. One study published in the British Journal of Educational Psychology found that students who developed a fear of failure early on were more likely to cheat to succeed and only wanted to do well to validate their self-worth.

When you're a child, it's only natural to get anxious in crowded, open spaces. But this fear plagues adults and children alike: According to Medical News Today, an estimated 1.8 million Americans 18 years and older live with a fear of crowds or of being outside alone. And we don't just mean a fear of walking through Times Square (because who doesn't have that?); for people with agoraphobia, even just taking the elevator proves to be difficult.

If you're part of the 73 percent of the population inflicted with a fear of public speaking, or glossophobia, then you likely empathize with the scene in The Princess Diaries when Mia Thermopolis runs out of the room in the middle of a presentation, about to throw up from anxiety. According to the National Social Anxiety Center, this fear is somewhat primitive, as our ancestors faced death when they were rejected from their tribe.

Just the sight of blood is enough to make someone with hemophobia pass out. Children with overbearing or anxious parents are more likely to experience this phobia—and unfortunately, it's likely to persist beyond puberty, as an estimated 3 to 4 percent of the population struggles with the aversion.

Few scientific studies have been done to determine just how many people suffer from this particular phobia, but one poll from the National Association of Sleep Comfort and Coziness (NASCC) did find that a staggering 87 percent of Americans won't sleep with their feet outside of the blanket, for fear of being snatched up by The Boogeyman. It might sound crazy, but we've watched enough horror movies to know not to trust that empty space under our beds.

Most of us are at least a little spooked after sitting around the bonfire listening to ghost stories that may or may not be folklore. But when it comes to the paranormal, some of us experience anxiety on an entirely different realm. And this crippling fear, known as phasmophobia, is positively correlated with a fear of dying, according to a study from Chapman University.

Alien abductions are quite common in The Sims, but they're nonexistent in the real world. And yet, a surprising number of people are afraid of extraterrestrials flying down in their UFOs and beaming us up with rays of bright lights. Even the brilliant Stephen Hawking was notoriously fearful of meeting another form of life, saying: "Meeting an advanced civilization could be like Native Americans encountering Columbus. That didn't turn out so well."

As a kid, your fear of going to the doctor is simple: The doctor is that person who gives you ouchies. But as an adult, it's a bit more complicated. According to Dr. Barbara Cox, our post-adolescent anxieties about going to the doctor generally stem from our fears of receiving bad news.

"Many people feel anxious because they fear the unknown, and they let their imagination run wild," Dr. Cox told NBC News. "They may imagine a worst-case scenario, when in fact going for, say, an annual check-up is the best prevention."

Nobody enjoys taking a test. But for some, this loathing comes from a place of severe anxiety, in which taking a test invokes nausea and feelings of helplessness and anger. In such cases, the fear of failure seals a person's fate, as they are too anxious to even finish the exam.

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