Personality traits are 50 percent heritable. Yes, can you believe it. Studies have shown that you and your loved one's personality traits are genetic. So your uncle or your neighbor that have an angry disposition is born with it. Or, your child that is shy or a socialite really did pick these genes up from you and your partner (or somewhere else down the line). HUH! How is this possible? Oh my! I guess this means I can't change this 50% that is heritable. Well, as a matter of fact, yes you can. Let's not chalk it all up to, "I was born with it and now I can't do anything about it."
Let me clarity. Let's say you are born a "suppressor" - you deny feelings of anxiety, anger, sadness, and fear. You try to avoid bothersome thoughts in hopes they just blow over. Okay, this is all fine. And, now, maybe you can become more accepting to yourself and others just knowing that your circumstances didn't create "all" of your 'habits.' What a relief that is!
Anyways, let me first tell you the unhealthy benefits of this trait. By holding onto negative emotions, you're going to make yourself sick. I'll give you a description. Besides creating an unhealthy mental and emotional state, you begin to shut down your immune system, too. No wonder there is a list an arm length long of immune disorders! With strong emotion, you activate the sympathetic division of the autonomic nervous system for "fight and flight" producing the release of epinephrine and nor-epinephrine from the adrenal medulla. In addition, the hypothalamus initiates activity along the HPA (hypothalamus-pituitary-adrenal cortex) axis for increased energy releasing chemical messengers. This chain reaction causes the adrenal cortex to secrete 'cortisol' and other hormones that elevate blood sugar and protect the body's tissues from inflammation in case of injury. This is all good when you are at risk: a bus headed your way or confronted by a bear. Your body goes into action, and from there, you take action - you move, and you move quickly!
However, strong emotions "stuck" inside of you because you want to pretend you are "fine" and that "nothing bothers you" will begin to suppress your immune system. This HPA axis of increased energy, when activated for a long-term, can cause harm to your body.
So now what? Well, environment is the other 50%. You do have a choice to help yourself, and you can improve your state and health. Your trait doesn't have to "rule" you. What are you going to do about the suppressed emotions? Confessing. Another way of saying this is talk - let it out by writing in your journal or talk to a qualified professional. See what works for you. Sometimes best friends are nice; however, there will be biases and maybe even judgment. By confessing or by talking, eventually, and what's most important, you are letting go of negative emotions that are buried inside of you. Doing so will give you a different perspective on the situation, yourself, and others. Confessing your worries and fears can reduce the chance of illness if it produces insight and understanding. Conversely, confessing each week to a friend over drinks without a resolution will only continue to hinder you and your health.