"All superficial comparisons to the contrary, Oliver Sacks and I are really quite dissimilar," said Dr. Harold Klawans, in his essay "My Lunch with Oliver." He and Sacks were both neurologists, both with special interests in movement disorders and Parkinson's disease, and both writers. "The brain and how it functions is to Oliver a philosophical issue... I try to ask simple questions." Klawans's questions are not really "simple," but they're about evolution and development instead of philosophy.
In his clinical practice, Klawans thought about the evolution of the brain to try to understand his patients' problems, and vice versa. His theme throughout is that brain development is about windows of opportunity: many things can only be learned in certain periods, and after puberty in particular the brain has been largely "pruned to shape," so that skills like language and music may never be properly acquired.
The cavewoman of the title is the one who stayed home taking care of the babies while Man the Hunter was off spearheading the Ascent of Man (in what Stephen Jay Gould, one of Klawans's favorite writers, calls an "evolutionary just-so story"). Not so, says Klawans: because the window of opportunity for learning language is in childhood, especially early childhood, language must have arisen between mothers and children: "though few defend the Cavewoman, we all speak our mother's tongue." --Mary Ellen Curtin