Brains of addicts are inherently abnormal: study It is interesting how the scientists doing the research see only two possibilities in explaining behavior: social environment or genetic predisposition; what ever happened to "moral choice"? Or maybe there is only a predisposition to addiction and their behavvior cemented this predisposition by altering their brain even further by their behavior? It has been shown that behavior affects brain development and shanges it even in adulthood over years of repeated behavior. I feel very skeptical that the brain DETERMINES our behvaior, but only can stack the deck some so that we are more likely to follow in that direction. But all of us always have a choice with each thing we do.