There have always been traits that genetics cannot explain, which are frequently ascribed to environmental conditions—that is, the concept of “nurture” rather than “nature.” Croxton disagrees and says that he believes that one’s personality traits are also products of nature. They’re unique and original to each person, he argues, and they stem from an ongoing genetic power struggle that stretches back to the early days of our species. Furthermore, he says, they’re tied to the gendered halves of our brains: “Anatomical gender is our external reproductive identity while neurological gender is our internal ancestral legacy expressed as a blend of ‘maleness’ and ‘femaleness’ in the respective hemispheres of the brain: our ‘two minds.’ ” Essential to his theory, he says, is understanding the way that DNA (genetic material) and RNA (epigenetic material) collaborate to create a species that’s shaped by the past yet retains flexibility for future development. Croxton bolsters his assertions by taking readers through a psychological history of civilization, from Neolithic warfare and societal organization to the rise of self-awareness and religion. Along the way, he charts the neurological traits of “male” and “female,” describing how their symbiotic interaction shaped the ascendency of man from an ape of the plain to the master of the Earth. Some readers may take issue with the designation of the right hemisphere as female and the left as male. But although this distinction isn’t entirely semantic, people may miss Croxton’s engaging larger point if they focus solely on such gender-political issues: by elevating the creative, trusting right brain to the level of the destructive, dominating left brain, he says, Homo sapiens was able to pull ahead of other left-brain–dominant hominid groups. Croxton pursues this argument with recent findings from the fields of neurology, psychiatry, and anthropology. His strategy is wonkish and minutiae-based, and readers may sometimes feel lost in all the data. Even so, this book offers a thoughtful presentation of an intriguing theory.
A thought-provoking explanation for the origins of personality.