Whoever said, "There's a sucker born every minute" is guilty of gross underestimation. Each minute about seven babies are born in the United States, and the way I figure it, at least half of those babies grow up to be suckers. (And I don't mean bottle suckers.)

No, I'm talking about people who are easily confused. Tricked. Bamboozled. Hornswoggled. There are a lot of them, ranging from ancient warriors to well-diggers to modern-day Internet users like you. Heck, you might even be a sucker yourself. You're not alone.

It's not just April Fool's Day when people get duped, either, although that has been the historical day for hoaxes since 1582, when Pope Gregory XIII decreed that the new year would start on January 1 instead of April 1. People who continued to celebrate New Year's on April 1 were teased with gag gifts and invitations to nonexistent parties. Mean! But true.

We call them April Fools, except in France, where they're called April Fish (Poisson d'Avril). The French called them this because the traditional joke was to tape a paper fish to the back of a friend. I guess it's the French equivalent of a "Kick me" sign.

People have been made to believe everything: that giants have walked the Earth, that mermaids have swum its seas, that Manhattan is sinking, and that the Eiffel Tower is for sale (again).

People have even been convinced that four-foot, furry men with batlike wings inhabit the Moon.

Do you think you're above being taken for a ride? Maybe you are. But then again, maybe not. To understand why, it helps to know why otherwise respectable people have been suckered by crazy stories time and time again.

Based on famous hoaxes from history, I've come up with three reasons people get tricked. I call them the telltale signs of suckerdom:

• general ignorance
• overconfidence in authority
• greed

Ignorance is bliss--for charlatans
You know what they say: "No one ever went broke underestimating the intelligence of the American public." As cynical as that view is, there is some truth to it. Giant truth, actually.

In 1869 two workers digging a well at the Cardiff, New York, farm of a man named "Stub" Newell stubbed their shovels on what they thought was a rock. Instead, it turned out to be a ten-and-a-half-foot petrified giant. It was a phony planted there by Newell and his partner, cigar manufacturer George Hull. But newspapers covered the find, scientists confirmed its authenticity, and before long, Newell and Hull had sold tens of thousands of tickets to curious onlookers at 50 cents apiece.

Even American showman P. T. Barnum, who is usually credited with the "suckers" quote, sought to rent the Cardiff Giant for $60,000 for a mere three months--not because he was a believer, mind you, but because he thought he could make his money back and then some. When the owners turned him down, Barnum went ahead and displayed a copy, which he portrayed as real--and he earned a lawsuit from the owners of the genuine artificial giant.

So why did people believe the giant was real? Because they didn't know how fossilization works. If the giant had been a petrified man, the fossil would have shown his bones--not the hardened flesh of what used to be his face.

Not just howling at the Moon
The now-defunct New York Sun is probably best known for an editorial written to a little girl named Virginia, who was wondering whether Santa Claus exists. "Yes, Virginia, there is a Santa Claus," the newspaper proclaimed.

But, 62 years before that, in 1835, the Sun carried the sensational story detailing the discovery of life on the Moon. And not just any life: humanoid creatures with wings, yellowish faces ("an improvement upon that of the large orangutan"), and curly hair styled in two circles over the temples.

The paper attributed the discovery to eminent astronomer Sir John Herschel and was supposedly reprinting a report from the distinguished-sounding Edinburgh Journal of Science.

Readers were frantic. A group of missionaries supposedly wanted to travel to the Moon to civilize the bat people. It wasn't until rival newspaper editors called the Sun on the series that Sun editors admitted the hoax. (And interestingly enough, circulation didn't go down. Apparently, the public was amused.)

So, despite what Virginia's father told her--"If you see it in the Sun, it must be so"--not everything that gets printed in newspapers and magazines is true.

While journalists generally don't make things up, it doesn't mean they're immune to printing incorrect information, even if their intentions are good. And there have been some spectacular cases of journalists making stuff up entirely--not just in cheesy tabloids, either. It's less common that false information is attributed to a credible source, as it was in the case of the hairy moon-bats of 1835. But in that instance, Sir John was in Africa--and they couldn't exactly e-mail him for confirmation.

This is why you shouldn't believe everything you read and you should be careful which sources of information you rely on.

Probably the most famous case of overconfidence in authority was triggered by Orson Welles's The War of the Worlds radio broadcast. People really believed Martians were attacking New Jersey. And, lest you think this is something that only our grandparents would fall for, remember how many people argued that The Blair Witch Project was a real story.

Greed is good?
Greed is at both edges of the sucker sword. Greedy hucksters make money off of people who are also greedy, usually by offering things that are too good to be true or too easy to be real.

History has many examples of this. For example, one con man sold the Eiffel Tower not once but twice to scrap metal dealers looking to make a buck from the Paris landmark. The con man, "Count" Victor Lustig, picked the guy who struck him as being the most anxious to get ahead from the secret sale of the tower.

Named Mr. Poisson, which is French for "fish," the victim was so embarrassed to have fallen hook, line, and sinker for the story that he never turned Lustig in. I'll bet Mr. Poisson was dreading the April Fish jokes, so I can understand his silence. Eventually, Lustig sold the tower to another sucker, and he later wrote a ten-rule manifesto for tricking people.

Similarly, you'd think the Trojan warriors presented with the giant wooden horse would have wondered why their Greek enemies were offering such a fine gift after so many years of war. Unfortunately for the Trojans, it contained their ruin--a small army of deadly soldiers.

The expression Trojan horse has found a new use these days: for computer viruses (a very modern way to get suckered). These viruses masquerade as legitimate files, but when they are opened they wreak havoc on your computer.

So there you have it--my top three reasons why people get suckered: ignorance, overconfidence in authority, and greed. But there are ways you can avoid becoming a fool--in April, or any time.

• Remember: If something seems too good to be true, it probably is.
• If someone makes a fantastic claim and cites an "expert" source, see if you can find another expert who agrees before you believe it. (This is true whether it's men on the Moon or promises that you will lose 30 pounds in 30 days.)
• And finally, keep reading and learning. The more you know about the world around you, the less likely you are to get reeled in like poor Mr. Poisson.