How confident are you? That might seem like a simple question, but it isn't, because we use the word confident to describe two different things. One type of confidence is social confidence, our sense of comfort in social situations and our expectation that others will accept us. The other is epistemic confidence, the confidence that you're correct in your opinions or conclusions. 

In other words, if you can walk into a room full of strangers feeling relaxed, with your head held high, and easily start a conversation with the first stranger you see, you have social confidence. If you are absolutely sure that your approach to marketing your company's product will work better than any other, then you have epistemic confidence.

In a fascinating piece at CNBC.com, Julia Galef, host of the podcast Rationally Speaking and co-founder of the Center for Applied Rationality, broke down the two types of confidence. And she cited experiments that show people with social confidence are more likely to be perceived as confident, capable, and likable than those displaying epistemic confidence. But I believe the difference between the two types of confidence are even more important and far-reaching.

Why social confidence leads to success

I've always believed that the ability to feel comfortable talking with strangers is a superpower. One reason I believe that is because it's worked that way for me. It's allowed me to land new clients. It's gotten me any number of interviews and other help that I wanted. It allows me to make the most of a simple introduction or a chance encounter, and to work the room during an event so I can pick out the people I most want to meet and then meet them. (There's a lot more about this in my new book, Career Self-Care.) If you also consider the research that shows people with social confidence are seen as more likable and capable, it's easy to see why social confidence is a huge advantage in the business world.

Why epistemic confidence leads to failure

As Jeff Bezos and others have observed, the smartest people are often the ones who are least set in their opinions and most open to changing their minds. Galef notes that Steve Jobs was famous for his ability to change opinions abruptly and completely. It's easy enough to see how, in a rapidly changing world, having the flexibility to rethink your beliefs when that's warranted could be a real plus, while sticking doggedly to yesterday's certainties might drag you down. 

How to be the right kind of confident

How can you develop your social confidence? As with many things, it helps if you practice. So look for opportunities to be in social situations that put you outside your comfort zone--just a little bit. Arrive armed with some conversation starters that will help get you talking with people you've just met. Volunteer to give presentations or otherwise put yourself in front of an audience--again, a small one at first. The more you can rack up positive experiences like these, the bigger your social confidence will grow.

Although it's more difficult, it's very worthwhile to challenge your own epistemic confidence as well. Next time you hear yourself declaring that you know something to be absolutely true, pause for a moment to ask yourself how you know that it's true, and whether any circumstances have changed that might make it less true than it used to be. It will help if you surround yourself with people who have different backgrounds and viewpoints than you do, and who are willing to disagree with you if they think you're wrong, or that you haven't considered all the angles.

There's a growing audience of Inc.com readers who receive a daily text from me with a self-care or motivational micro-challenge or idea. Often they text me back and we wind up in a conversation. (Interested in joining? Here's more information and an invitation to a free two-month trial.) Many are entrepreneurs or business leaders, and they tell me how vital it is to switch to a new approach quickly when needed. And here's something else I've learned from them--truly confident people are never afraid to change their minds.