Twins and the Mind-Brain Problem

If proponents of Mind-Brain Identity theory are correct then all of our ‘mental’ events are reducible to brain states. We don’t have a mind at all; we are purely physical. All of our thoughts, dreams, our personality and character, our very consciousness are ‘events’ that exist due to physical (chemical and electrical) interactions within the folds of our brain. 

This theory suggests all sorts of strange possibilities, most of which are pure fantasy. For instance, if we produced a pair of human clones and raised them identically then we should expect them to be identical in every way. Since each would have identical brains and experienced identical life circumstances, their personalities and consciousness would also be identical. Talking to one would be exactly like talking to the other. Each would have identical dreams and desires, fears and doubts. 

Though this experiment is impossible today, and unethical anyway, we can explore a version on a theme by looking at twin studies. To investigate the mind - brain problem, studies have been done on identical twins that were separated at birth and raised in separate environments. Some of the similarities between these twins are astonishing.