Fear holds us back, we all know, but what exactly are we afraid of when we don’t implement that business idea, email that bigwig or approach the attractive stranger across the bar?

The answer to all these questions is the same: we fear rejection.

Humans are social animals and the pain of being told no, losing relationships, or having others think we’re foolish is very real, and very limiting. But it’s also incredibly hardwired into us (just think how you’d fare back in hunter gatherer days if you alienated your group and ended up alone). Is there any way to inoculate yourself against this fear of rejection so that you can boldly pursue all the things you’re currently too scared to tackle?

One man thinks he’s found a way. But be warned, it’s not pleasant.

Entrepreneur Jia Jiang was crushed when an investor turned him down, opting not to put money into his startup. Feeling hurt and angry, Jiang almost gave up his dream of building a business. But eventually he decided the problem wasn’t the rejection, per se, it was his inability to take it. He prescribed himself some fairly radical therapy.

Every day for 100 days he would ask a perfect stranger to do something outrageous. He asked a police officer if he could drive his car. He asked a flight attendant if he could make the safety announcement. He asked Black Friday shoppers if he could cut in line. The answers were obviously ‘no’. Jiang took short videos of these encounters and posted them to his blog. He called the whole project ‘Rejection Therapy.’

What did Jiang learn from all this rejection? He outlined five takeaways for MTV (of all places):

  • In life, rejection is certain. Once you accept this fact, it will be easier to anticipate and to overcome moments of rejection.

  • Detach yourself from the results of a request, and you will become more confident and increase your chance for acceptance, or a “yes.”

  • The worst part of rejection is the fear of it. Do not let the fear prevent you from making your request.

  • Rejection is nothing more than someone else’s opinion. We should never consider it as truth about ourselves.

  • If we talk to enough people without giving up, a rejection will become an acceptance.

With his newfound courage Jiang plans to continue to grow his company and find an investor, he told BusinessWeek.

So if this only one man’s crazy notion or is the kernel of the idea -- that we can teach ourselves to fear rejection less -- more broadly applicable? The idea actually has some scientific weight behind it. Scientists call tackling terrifying challenges until they’re no longer terrifying ‘implosion,’ and several famous faces endorse the technique. Comedian Will Ferrell told People magazine that "in college, I would push an overhead projector across campus with my pants just low enough to show my butt. Then my friend would incite the crowd to be like, ‘Look at that idiot!’ That's how I got over being shy,'" Conan O’Brien claims to have begun doing stand up because nothing terrified him more.

Could some form of ‘rejection therapy’ help you get over your fear and pursue your dreams?