Genes don't tell the whole story..
The biological complexity of life..
Turning genes on and off..
The triggers of what causes this process??
While they are looking toward the environmental causes..
I look toward the harm of injecting neurotoxic heavy metals and other substances into a baby then a toddler then a child and adult if they can convience one to do it.
That it's completely safe to do so.
But lots of people don't believe that to be true anymore.
And here is two identical twins and look at the differences..
In them.

Ghost in your genes..
NOVA..

http://www.youtube.com/watch?v=YVwhJXqIG9c