I think McG is correct about left brain dominance in modern culture. However, his analysis of psychiatric illness is deeply flawed and leaves out what most studies--even the imaging studies he does--tell us. Namely, that the prefrontal cortex is at the root of the mental illnesses humans suffer from. It is too complex to go into but to give an example; the PFC controls attention and is the problem in ADHD. It is also the source of problems in autism. This omission is rather large and hard to understand. For a full discussion of this issue see "Frontal Fatigue. The Impact of Modern Life and Technology on Mental Illness."