Scientists used to think you were stuck with the personality you were born with. But a recent study shows that people do change as they get older. They surveyed 130,000 people on five personality traits: emotional stability, extroversion, agreeableness, self-control, and openness to new experiences. And they found distinct differences between age groups

People in their 30s are more agreeable and reliable than those in their 20s. Those in their 40s are more confident, and have more leadership qualities. And everyone gets less neurotic, and more good-natured, trusting, and warm as they age

But can you change your personality on purpose? You can, if you work at it. Here's how to be the person you want to be:

  • Become more assertive. If you're afraid to speak up at a party, or talk to a stranger in line, try this: Mentally jump to the end of the encounter. And think about how you'd feel if you walked away without saying anything. Focus on that regret, and you'll talk in spite of yourself.

  • Practice patience.Then, become more patient. Next time you're frustrated by how long something is taking, try noticing 5 things around you. That simple act of observation will distract you. But even better, it will bring you back to the here and now.

  • Get happy. Make positive changes in your personality if you practice being more cheerful. Once you push yourself to answer the phone with a cheery hello, and smile at the receptionist when you get to work, you'll find it easier and easier to have a sunny disposition.

  • Lose the fear. If you'd like to become less fearful, think about this: The more risks you take, the more risks you'll want to take. So, say you're afraid of public speaking - take a class, or join Toastmaster's so you can learn to make a speech without losing your lunch.

If you'd like to go further, check out the book Secrets You Keep From Yourself: How to Stop Sabotaging Your Happiness by Dan Neuharth.