For most of us, our knowledge of genes is pretty slim. The extent of what we know is that they are passed down to us from our parents, they make up characteristics of our behavior and appearance, and we cannot control them. Whether it be your father's temper, or your mothers "good looks", everyone deals with the positive and negative affects genes bring sooner or later in life. Every one of the roughly 100 trillion cells in our bodies contains every one of our genes. I always assumed that since genes are always present, they are always in action. However, I was wrong.
As it turns out, environmental experiences actually turn genes on and off throughout development. This phenomenon is called gene expression; it is considered one of the most significant discoveries in psychology over the past several decades. Our genes act as an "on" and "off" switch. Only some of them are active at any given time, and it sometimes takes environmental experiences to flip their switches to "on."
Our text books shares an example of this. Children with genes that predispose them to anxiety may never become anxious unless a highly stressful event, like the death of a family member in early development, triggers these genes to become active.
goro0014: January 2012 Archives