What do we need to reconsider with respect to the nature of the ape mind? Why did the human brain undergo an accelerated period of evolution that left it far more sophisticated than the apes? As I understand the hypothesis, Tim Crow associates deviations of psychological function with psychosis, that is, schizophrenia, Asperger syndrome, and autism, and the capacity for language and emotional expression.1 Indeed, Crow attributes psychosis to variation in the genes controlling hemispheric asymmetry that has led, by the mechanism of sexual selection through progressive delay in maturation (neoteny), to increased brain size and intelligence, a sexual dimorphism in age of onset of psychosis that corresponds to an extreme of development of cerebral asymmetry, for example, a failure to establish dominance in one or other hemisphere, testable by X-Y homology.2
Nonetheless, Marc Hauser noted that homologs to Broca's Area have been found in macaque and squirrel...