Napoleon Hill is the grandfather of self-help authors, inspiring the likes of Oracle founder Larry Ellison, media mogul Oprah Winfrey, and performance coach Tony Robbins.

His 1937 book "Think and Grow Rich" is one of the top-selling books of all time, with around 100 million copies sold worldwide. The simple reason it's sold so well is because his practical insights into how successful people carry themselves — primarily based on his many months spent interviewing the industrialist Andrew Carnegie — are timeless, straightforward, and useful

In one of his essays, "Develop a Pleasing Personality," as collected in "The Science of Success," he focuses in on how to have a "million-dollar personality."

Below, we've included Hill's 14 habits of people who are so likeable that others go out of their way to help them.

They develop a positive mental attitude and let it be seen and felt by others

It's often easier to give into cynicism, but those who choose to be positive set themselves up for success and have better reputations.

They always speak in a carefully disciplines, friendly tone

The best communicators speak deliberately and confidently, which gives their voice a pleasing sound.

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They pay close attention to someone speaking to them

Using a conversation as an opportunity to lecture someone "may feed the ego, but it never attracts people or makes friends," Hill says.

They are able to maintain their composure in all circumstances

An overreaction to something either positive or negative can give people a poor impression. In the latter case, says Hill, "Remember that silence may be much more effective than your angry words."

They are patient

"Remember that proper timing of your words and acts may give you a big advantage over impatient people," Hill writes.

They keep an open mind

Those who close themselves off from certain ideas and associate only with like-minded people are missing out on not only personal growth but also opportunities for advancing their careers.

They smile when speaking with others

Hill says that president Franklin D. Roosevelt's greatest asset was his "million-dollar smile," which allowed people to lower their guards during conversation.

They know that not all their thoughts need to be expressed

The most likeable people know that it's not worth offending people by expressing all their thoughts, even if they happen to be true.

They don't procrastinate

Procrastination communicates to people that you're afraid of taking action, Hill says, and are therefore ineffective.

They engage in at least one good deed a day

The best networkers help other people out without expecting anything in return.

They find a lesson in failurerather than brood over it

People admire those who grow from failure rather than wallow in it. "Express your gratitude for having gained a measure of wisdom, which would not have come without defeat," Hill says.

They act as if the person they are speaking to is the most important person in the world

The most likeable people use conversations as an opportunity to learn about another person and give them time to talk.

They praise others in a genuine way without being excessive

"Praise the good traits of others, but don't rub it on where it is not deserved or spread it too thickly," Hill says.

They have someone they trust point out their flaws

Successful people don't pretend to be likeable; they are likeable because they care about their conduct and reputation. Having a confidant who can be completely honest with them allows them to continue growing.

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