There is often the argument of nature vs. nurture when it comes to why people are the way they are. The general consensus is both are very important, and it is true. A poor environment can result in very poor behavior if the kid is impressionable and not a very strong independent thinker.
In terms of environment, a person exposed to ridicule and bullying will either develop a thick hide or succumb to the pressure. Those who are “different” from the norm are often exposed to more teasing than others. Having a different gender preference than others is often one such cause of ridicule, but there are those who develop very thick skin and become highly feisty.