Imagine Bailey and Pillard grabbed a rock and went to the top of a mountain. They slowly rolled the rock through the snow until they had a 20 foot snowball. At this point they told everybody: "Hey, look at this evidence we've gathered." And everybody, assuming the snowball contained some substance, accepted their evidence at face value.
But in time the snowball melted and Bailey and Pillard were left holding the same rock with which they started, and that rock is just a rock, nothing more.
That's why the Gladue quote I provided earlier is so appropriate: "If research is buried it will only come back to bite us later."
A .5 correlation is called a huge role.
Think about that rock. Besides that, Bailey and Pillard would disagree with you that genes play a huge role.