There has been an argument on personality and individuals development for a long time. The key point of the dispute is which factor plays a more important role, genes or training after birth? In my opinion, the latter is the crucial complication, though genes are significant.
Although genes have great effects on ones personality, environment plays a more important role in his further development. Lets take an experiment for instance. There was a research on a couple of identical twins who were born in a big city, but they were separated after birth. One was taken to a poor suburban area, while the other remained in the city. Fifteen years later,surely, the one in city grew tall, strong, extroverted and well educated. By contrast, the other was short, thin, introverted and nearly illiterate. This well demonstrates the importance of nurturing.
In addition, education, especially early education, is another key factor.When children are very young, they try to imitate their parents behaviors, and run into some manners. After going to school, different education systems and even different courses students taking will make influence on their personalities and ideas. Students of science and technology subjects are good at logical thinking, while students of arts usually think in terms of imagine.
As you can tell from my comments above, no one can choose his nature,but one can be greatly successful after striving for himself or being well educated.And no one can be successful relying on his genes without good environment. So, in my opinion, environmental influence and education will ultimately decide ones personality and development.