There is no Left Brain/Right Brain divide. It's a myth. They work together.
The left-brain right-brain myth will probably never die, because it has become a powerful metaphor for different ways of thinking—logical, focused, and analytic versus broad-minded and creative. Take the example of Britain's Chief Rabbi Jonathan Sacks talking on BBC Radio 4 earlier this year. "What made Europe happen and made it so creative" he explained.
As well as having metaphorical appeal, the seductive idea of the right brain and its untapped creative potential also has a long history of being targeted by self-help gurus peddling pseudo-psychology. Today the same idea is also picked up by the makers of self-improvement video games and apps. The latest version of the Faces iMake-Right Brain Creativity app for the Ipad, for example, boasts that it is "an extraordinary tool for developing right brain creative capabilities."
There is more than a grain of truth to the left-brain right-brain myth. While they look alike, the two hemispheres of the brain do function differently. For example, it's become almost common knowledge that in most people the left brain is dominant for language. The right hemisphere, on the other hand, is implicated more strongly in emotional processing and representing the mental states of others. However, the distinctions aren't as clear cut as the myth makes out—for instance, the right hemisphere is involved in processing some aspects of language, such as intonation and emphasis.