How the Left Hemisphere Colonized Reality

If we are to believe the latest conclusions of Tony Wright (speaking above in a National Geographic documentary) the left brain hemisphere has not simply dominated a more passive right; rather, over time, it has changed our neurochemistry and neural structures to support its own ascent. In his new book, Left in the Dark, Wright argues that "humanity is suffering from species-wide brain damage" and this damage is the "root cause of our obvious insanity."
According to current thinking cerebral dominance is the product of adaptive selection and has resulted in one side of our brain (the left) acquiring specialist abilities such as speech and rational or conceptual thinking. With these 'advanced' skills the left hemisphere has come to dominate our thinking, behaviour and psychology. In effect our mind and sense of self or who we think we are is primarily a product of the left side of our brain. Of course the conclusion that our left hemisphere has specialised and advanced abilities is, by definition, a conclusion reached by our left hemisphere! Lets suppose just for a minute that our left hemisphere is a hormonally retarded, structurally damaged, perceptually limited and psychologically deluded version of our right hemisphere and its rise to dominance was driven by fear and the need to maintain a sense of control due to its increasing damage. In effect cerebral dominance is a symptom of a neurodegenerative condition rather than an advanced adaptive trait.
On the one hand, this feels a bit like a rehashing of decades-old complaints about left-brain, dominator culture memes wiping out the goddess herself. But at least these are grounded in accepted science. If anything, it's a left-brain-argued case against the left brain.