It is arguable that no figure has had a bigger impact on the emergence of the multibillion-dollar personal improvement industry than Napoleon Hill, author of the 1937 book Think and Grow Rich.

It was Hill who first wrote about the still-popular concept of Mastermind Groups, which involves entrepreneurs and executives getting together outside of work to swap ideas and share advice. Hill also introduced the idea of the Law of Attraction, which states that if you focus your attention and on getting the things you want, you will attract them to you. In many ways, Hill was the direct inspiration for the bulk of the gurus who now fill our airwaves, shops, and stages, including Tony Robbins and Robert Kiyoaski.

Judging from his influence, one might assume that Hill's perennial bestseller was the capstone to a blockbuster career. The record shows otherwise. Before becoming the Ur-author of the self-help movement, Hill's path in life was marked by a chain of shady and embarrassing failures. His attempts in business typically ended in bankruptcy, and were marred by charges of check altering, the sale of unlicensed stock, and other forms of outright fraud.

Even his greatest success was built on a fabrication. According to Hill's now familiar story, Think and Grow Rich grew out a conversation he had had with steel tycoon Andrew Carnegie, at the end of which Carnegie set up interviews between Hill and the leading business minds of the day--including Henry Ford, Alexander Graham Bell, and Thomas Edison. The idea was that the author would distill the wisdom of these great men into easy-to-digest success secrets for the benefit of the general public. In fact, Carnegie's most notable biographer, David Nasaw, says there is no record of the two men ever having met. Yet by stating this claim with great confidence within the covers of a book, Hill virtually ensured few people would ever question it.

How he did it.

For the better part of history, owning a book was a privilege restricted to an elite few. Being the author of one was, for the vast majority of human beings, nearly unthinkable. Prior to the invention of the printing press, every copy of every book was literally written out by hand. Even after the mass production of books became possible, getting one out into the world and distributed on any kind of significant scale still required tremendous effort and organization. An extensive network of publishers, printers, editors, attorneys, and agents sprung up to service the demand. With such extensive infrastructure, it became essential to determine which books were worth the time and expense that was required to produce and promote them. As such, publishers became uncommonly adept at identifying which figures deserved to have their ideas heard. In other words, to become an author, you needed to have credibility.

When it comes to getting people to follow you, establishing credibility is of the utmost importance. In a series of experiments, psychologists Carl Hovland and Walter Weiss presented subjects with controversial arguments that were at odds with the opinions they held at the outset of the sessions. In some instances, these opinions were related by everyday people in street clothes with unknown backgrounds. In other cases, the arguments were presented by people displaying overt credentials and symbols of authority.

The subjects who received the controversial opinions from the more visibly credible figures changed their minds more often than those who had received the information from a person on the street. It is worth keeping in mind that none of the experts presenting these arguments ever offered any real proof of their credentials. They simply displayed the outer signs of credibility. And that was enough.

Why do otherwise intelligent people so readily trust the ideas and dictates of those displaying the symbols of credibility, regardless of whether that credibility is backed up in any meaningful way?

We simply cannot help it. It is how our brains are wired.

Popular science writer Leonard Mlodinow explored this concept in depth in his own bestselling book Subliminal: How Your Unconscious Mind Rules Your Behavior. "We don't have the time or the mental bandwidth," he explains, "to observe and consider each detail of every item in our environment. Instead we employ a few salient traits that we do observe to assign the object to a category, and then we base our assessment of the object on the category rather than the object itself." In other words, our brains don't really care about digging into all the details that go into making someone a credible expert. What our mental circuitry does crave is a shortcut that proves the person we are thinking about following is smart, capable, and creative enough to lead us. When we find someone is a book author, it satisfies this need, regardless of how they got there.

Napoleon Hill's hidden law.

Despite his reputation as man who had cracked the code to what it takes to become immensely wealthy, it is now clear that Hill did not practice many of the virtues he exhorted others to live by. Still, in the end, he became a very famous and very wealthy man in his own time, and his estate still generates substantial income in ours.

When people study Hill to figure out how to become successful, it is worth considering that they might be looking at the wrong part of his story for clues. It turns out that Hill was not able to think, grow rich, and then write a book about it. Instead, he thought of a book, wrote it, and the riches followed.

To read more stories of history's greatest Hype Men, check out this, this, and this.