17 things keeping you from getting rich, according to a journalist who spent his career studying millionaires

Man thinkingRasstock/ShutterstockGetting rich is entirely up to you.

Prompted by the legendary businessman Andrew Carnegie, who turned a few nickels and dimes into a fortune, journalist Napoleon Hill researched more than 500 self-made millionaires over 20 years before releasing his 1937 bestseller, “Think and Grow Rich.”

In addition to boiling down the “secret” to building wealth in 13 principles, he revealed 30 “major causes of failure” that hold many of us back from getting rich.

Here are 17 that are still relevant today.

Lack of ambition.

You have to want it.

You have to want to aim above mediocrity, Hill says: 'We offer no hope for the person who is so indifferent as not to want to get ahead in life, and who is not willing to pay the price.'

Wealth doesn't simply appear. You have to work toward it with patience and persistence. A good starting point is to invest your money (the earlier the better), and let the power of compounding build your wealth. It doesn't take much time or effort, but it does require action on your part.

Not properly applying your education.

Take your formal education and apply it outside of the classroom.

A college degree won't cut it. Knowledge is only potential power, and will not become useful or lead to great wealth unless it is organised and applied to life, Hill emphasises: 'Education consists not so much of knowledge, but of knowledge effectively and persistently applied. Men are paid not merely for what they know, but more particularly for what they do with that which they know.'

Don't settle with your degree. Make it a priority to constantly learn knew things and challenge your mind. There's a reason that many of today's successful and wealthy people are voracious readers.

Not taking care of your body.

Make time for exercise.

'No person may enjoy outstanding success without good health,' Hill writes. It's no coincidence that many millionaires make time in their schedules to exercise.

If you haven't mastered your body, the good news is that many of the causes of bad health -- overeating, negative thoughts, and lack of exercise -- are completely under your control.

If you're pressed for time, try this 7-minute workout that you can do at home.

Lack of decisiveness.

Make up your mind and stick with it.

'Analysis of several hundred people who had accumulated fortunes well beyond the million dollar mark disclosed the fact that every one of them had the habit of reaching decisions promptly,' Hill writes.

On the flip side, 'People who fail to accumulate money, without exception, have the habit of reaching decisions, if at all, very slowly, and of changing these decisions quickly and often.'

Decisiveness is not just a trait of the wealthy, but one of the most important qualities a leader needs to possess. At the end of the day, making a bad decision is better than making no decision at all.

Choosing the wrong spouse.

Don't get married just because it seems like the right time.

Hill highlights this as one of the most common causes of failure. 'Unless this relationship is harmonious, failure is likely to follow,' he writes. 'Moreover, it will be a form of failure that is marked by misery and unhappiness, destroying all signs of ambition.'

His claims are backed by research. One study, by Brittany C. Solomon and Joshua J. Jackson of Washington University in St. Louis, shows that having a conscientious spouse can boost your salary by $US4,000 a year.

Not taking risks.

Caution with money is a good thing, but over-caution can backfire.

'The person who takes no chances generally has to take whatever is left when others are through choosing,' says Hill. 'Over-caution is as bad as under-caution. Both are extremes to be guarded against. Life itself is filled with the element of chance.'

When it comes to managing your money, it can be tempting to let your savings sit 'safely' in your bank account to avoid feeling repercussions from another stock market crash. However, investing your money is how you'll make more of it.

You'll want to do so wisely of course, and a good starting point is to look into low-cost index funds, which Warren Buffett and other investing experts recommend.

Hanging out with the wrong crowd.

The rich tend to associate with others who are rich.

'One should use great care to select an employer who will be an inspiration, and who is, himself, intelligent and successful,' advises Hill.

This concept extends beyond your boss and associates; it is also important to surround yourself with talented and driven people outside of work. Hill calls this creating a 'Master Mind' group.

We become like the people we associate with, which is why the rich tend to make friends with others who are rich.

Not narrowing your focus.

Focus on building wealth and don't let distractions derail you.

'The 'jack-of-all-trades' seldom is good at any,' writes Hill. 'Concentrate all of your efforts on one definite chief aim.'

If you want to get rich, you need to become obsessed with this desire, Hill says: 'Wishing will not bring riches. But desiring riches with a state of mind that becomes an obsession, then planning definite ways and means to acquire riches, and backing those plans with persistence which does not recognise failure, will bring riches.'

Lack of passion.

Enthusiasm is crucial to success.

'Without enthusiasm one cannot be convincing. Moreover, enthusiasm is contagious, and the person who has it, under control, is generally welcome in any group of people,' writes Hill.

The wealthiest people do not find success on their own; rather, they use their passion and energy to inspire others and push forward.

'Without passion, you don't have energy; without energy, you have nothing. Nothing great in the world has been accomplished without passion!' billionaire Donald Trump famously said.

Being closed-minded.

Be open to collaboration and new ideas.

'The person with a 'closed' mind on any subject seldom get ahead,' explains Hill.

You must be willing to continually collaborate with others, imagine new ideas, and innovate. The wealthiest and most successful people think differently.

To start thinking differently, do different things, expose yourself to different people, and value other ideas, says John C. Maxwell in his New York Times bestseller 'How Successful People Think.'

Lack of soft skills and inability to cooperate with others.

Mark Cuban.

'Most people lose their positions and their big opportunities in life because of this fault than for all other reasons combined,' warns Hill.

Building an empire takes people skills and charm just as much as it does strategy.

Mark Cuban put it bluntly in an Entrepreneur article about the keys to being successful in business: 'People hate dealing with people who are jerks. It's always easier to be nice than to be a jerk. Don't be a jerk.'

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