There is a certain amount of your behavior and sensitivities that is influenced by your genes - plus, of course, your childhood experiences, which can, for some, be called traumatic.
But it is also interesting to note how many people have chosen to rise above the "condition" and to not be stuck in a "post traumatic stress syndrome" kind of life. You can hear it in their conversations, as they sprinkle something into almost every conversation when they get a chance. "This is why I am the way I am. If you had a childhood like mine, then you'd understand or have problems, too." "I'm justified" - and therefore I choose to be stuck.
It is like any other trait that people have, you will be influenced by it, but you need not be a perpetual victim of it.
I would recommend that anyone who considers themselves to be highly sensitive to what is happening in their lives buy and use The Highly Sensitive Person's Workbook, by Elaine N. Aron, Ph.D.
A highly sensitive child one of the fifteen to twenty percent of children born with a nervous system that is highly aware and quick to react to everything. This makes them quick to grasp subtle changes, prefer to reflect deeply before acting, and generally behave conscientiously. They are also easily overwhelmed by high levels of stimulation, sudden changes, and the emotional distress of others. (You may wish to take the questionnaire to see if this is true of your child: Is Your Child Highly Sensitive?)
USEFUL FOR HIGHLY SENSITIVE PERSONS: