Personality

October 1, 2007
British psychologist Nettle (Happiness: The Science Behind Your Smile
) defines personality as a grouping of traits, partly genetically inherited, that remain stable throughout one's life. Drawing on his own research and others', he explores what he sees as the five dimensions of personality: extroversion, neuroticism, conscientiousness, agreeableness and openness to experience. This last, Nettle admits, is the most elusive; while it involves creativity, it also may include “restless unconventionality, supernatural beliefs and psychosis-like experiences”—exemplified by Allen Ginsberg's poem Howl
. Nettle also delves into evolutionary biology, showing how certain traits that were adaptive in one environment might become nonadaptive in another (e.g., the fight-or-flight response that was necessary for prehistoric humans facing predators is less desirable when manifested as road rage). In emphasizing the genetic component of personality, Nettle concludes, based on twin studies, that within normal families (with no violence or abuse) parenting “cannot have any measurable effect on child personality.” But overall, this is a well-researched, accessible, informative and sometimes (in its use of personal anecdotes) entertaining book that ends on a hopeful note: Nettle says that while our basic personalities don't change significantly after childhood, our behavior can.