Science will explain how but not why. It talks about what is not what ought to be. Science is descriptive not prescriptive it can tell us about causes but it cannot tell us about purposes. Indeed science disavows purposes.
They used to say it was bad for Indians to drink but it's bad for anybody. When they drink they lose their cool a lot of us. Like when we played with Sonny Boy I would never get paid you know. He would drink up all the money.