Our beliefs lead to our behavior. The way we think about the world and the things that happen to us affect the actions we take. Two people can experience the exact same stimulus and react in two totally different ways. Carol Dweck and her associates have developed a line of research to help us better understand the various types of beliefs we can have about ourselves and the world. She has identified a continuum she describes as having a Fixed Mindset or a Growth Mindset.
The easiest way to think about these types of mindsets is to look at them through the lens of failure. When somebody with a Fixed Mindset experiences failure they take it personally. As Dweck says, "Failure has been transformed from an action (I failed) to an identify (I'm a failure)." On the other hand, failure when you have a Growth Mindset is an opportunity to learn. Who do you think experiences the greatest amount of success in the long run?
The way we develop our particular mindsets has a lot to do with the type of praise or encouragement we were given when we were younger. Dweck has found that parents and teachers who praise a child's effort, instead of their accomplishments, help support a Growth Mindset. On the other hand, praising accomplishments or how "smart" a child seems to be can lead to the development of a Fixed Mindset. If you're constantly being praised for being smart and then run up against something difficult that takes effort then your "smartness" can take a hit. On the other hand, being praised for effort can result in a difficult task being seen as an opportunity to increase effort even further.
Effort is a key concept when talking about the difference between Growth and Fixed Mindsets. Being good at things is not the sole worry of someone with a Fixed Mindset. Instead, it's important to be good at things while also not having to spend a lot of effort. It's important to be perfect. As a result, most people with a Fixed Mindset stay firmly entrenched in what they know and what they already do well. They do not expand the boundaries of their abilities or interests because it would be a threat to their identity as a "smart" person.
As you can imagine, the Growth Mindset approach is largely the opposite. Increasing difficulty is not a signal to stop, but a signal that you're heading in the right direction. A Growth Mindset uses difficulty and setback as guideposts for where effort should be spent. In one study, children who tested as having more of a Growth Mindset had to be wrestled away from difficult puzzles and wanted information about where they could get more puzzles like the ones they were having trouble with so they could practice at home. Children with a fixed mindset couldn't get away from the puzzles fast enough. When faced with the opportunity to either complete a puzzle they had already completed successfully once, or to try a slightly harder puzzle, Fixed Mindset children were content to complete the same puzzle again.
Luckily, mindset, like any belief, can be changed. Your predilection for having a Growth or Fixed Mindset may be originally genetically set, but it appears to be able to be changed over time. An important first step is simply learning about Growth and Fixed Mindsets. Becoming aware of the difference and thinking about your own beliefs can set you in the direction of changing them to a more conducive approach. Another avenue to changing mindsets is to learn about the plasticity of the brain. Dweck has used this concept to develop a workshop and software program for adolescents that helps them learn about how the brain is like a muscle. Using your brain more strengthens it just like going to the gym and lifting weights strengthens muscles. This can help eliminate the belief that anything that doesn't come naturally or immediately is not possible.
I think one of the most interesting implications of this research into mindset has to do with happiness and success. There are lots of people with Fixed Mindsets who are wildly successful. Talent is completely separate from mindset and many people have an absurd amount of talent. There are also people with Growth Mindsets who are absurdly successful. What's interesting is that those successful people with a Fixed Mindset have expended all the time and effort into being successful because they are striving for some kind of external reward. Whether it be prestige, money, power -- a Fixed Mindset is not satisfied until it attains those. Somebody who is equally successful but has a Growth Mindset may reach the same level of success but it is a byproduct of the enthusiasm for what they do. They tend to be happier than those who have fixated on external proof of success (I wonder if obsessive/harmonious passion is related to Fixed/Growth Mindset at all?).
Looking at the way you deal with failure and success can help you figure out what kind of mindset you have. If you're unhappy with your personal development it's possible you've been operating under a Fixed Mindset. If you can shift that to a more Growth-oriented mindset you're likely to find greater success and be happier in the process.
Carol Dweck's book, Mindset: The New Psychology of Success, is a great place to learn more about this idea and get more ideas about how you can improve your own mindset.