QUIRK

Holmes (The Well-Dressed Ape: A Natural History of Myself, 2009, etc.) delves into the diversity of human personalities.

“[T]he key to personality is that there’s no single solution that answers every risk,” writes the author, who has shown a feisty, learned hand at decoding the brain’s workings for a popular audience. Half of our personality is genetically knit into our DNA (“personality isn’t personal. It’s biological. It’s a series of dials—Extraversion, Neuroticism, Agreeableness—each set to a different temperature”), while our environment calibrates the other half—nature and nurture. Holmes deploys the “Five Factor Model,” which breaks down personality into openness, conscientiousness, extraversion, agreeableness and neuroticism, each with various facets. This model is far from a scientific tool—it describes but does not explain the function of a personality facet—but it is one of the best guides available to our natural inclinations and for identifying risks for personality disorders. The author uses a template to examine many of these facets—how they are manifested in mice, then humans, and the facets’ evolutionary advantages. A relaxed, almost chummy, tone permeates the book (“Yeah, I was anxious from an early age”), which puts the reader at ease as Holmes describes neurotransmitters, brain regions and their role in personality formation. Less successful is the author’s template. Too often the personality traits don’t pertain to mice—“Mice are hard pressed to demonstrate every facet of Openness”; “mice don’t demonstrate much in the way of intellectual style”—and because much of this material is in the realm of conjecture, anecdotes abound, which can be entertaining and illuminating—the author’s scrutiny of addiction, for example—but can also be painfully obvious at times: “People with a strong imagination are able to stimulate their minds from within.”

An intriguing but hardly groundbreaking consideration of the qualities that distinguish us.