Parents have absolutely no (or very, very little) influence on the development of their children's personalities.
I was reading book called "What is Your Dangerous Idea?" (I recommend you read it too), which is a collection of essays from leading scientists answering the title question. Several of these essays caught my eye because they dealt with the bolded statement above, which happens to be a bit of a personal topic for me.
Currently, it is seen that parents have total control over their children's development. Parent's attempt to take some portion of credit for a child's accomplishments, and are always assigned some bit of blame for a child's failures or misdeeds. Good kids are seen to be the result of good parenting, and bad kids are seen to be the result of bad parenting.
This is an enormous amount of perceived power. As was said in Spider Man, with great power comes great responsibility. What was not said was that with great responsibility comes a great deal of mental anguish, stress, and pressure. Because parents are perceived to have such a high degree of power over their children's development, any half decent parent is put under the intense pressure of having to do it just right, and make no mistakes.
I would liken this pressure to having to defuse a live time bomb with no schematics, no help, and no knowledge at all of what to do. If that doesn't stress you out, you're abnormal.
There was also an argument presented in one of the essays that this view may ultimately be harmful to the parent-child relationship. There is no other kind of interpersonal relationship in society that consists of one member attempting to subvert, dominate, and ultimately change the other's personality. It is a highly manipulative set up to have as the basis for a relationship.
What are your feelings about this?