"Let's incorporate behavior. If someone has extensive frontocortical damage, how predictable is it that you'd note something odd about them, behaviorally, after a five-minute conversation? Something like 75 percent. Now let's consider a broader range of behaviors. How predictable is it that this person with the frontal damage will do something horrifically violent at some point? Or that someone who was abused repeatedly as a child will become an abusive adult? That a soldier who went through a battle that killed his buddies will develop PTSD? That a person with the "montane vole" polygamous version of the vasopressin receptor gene promoter will have numerous failed marriages? That a person with a particular array of glutamate receptor subtypes throughout their cortex and hippocampus will have an IQ above 140? That someone raised with extensive childhood adversity and loss will have a major depressive disorder? All under 50 percent, often way under."