Impulse: Why We Do What We Do Without Knowing Why We Do It

Why, though we see ourselves as rational beings, are we more likely to make decisions based on impulse rather than logic? The answer, according to Lewis (founder & director. of research, Mindlab Intl., Sussex Innovation Ctr.), is that impulsive thinking is the default mode of our "zombie brain." Impulsive thinking, outside our conscious control, takes priority over reflective, logical, and conscious thinking. Lewis reviews supporting research from psychology and neuroscience, discusses developmental aspects of infant and adolescent behavior, and presents several tests of impulsivity including the 2D:4D digit ratio, a finger measurement thought to correlate with risk-taking in males. Lewis further examines the role impulses play in falling in love, overeating, and spending, as well as violent and destructive behavior. His conclusions are sobering: most decisions are subliminal, self-control is influenced by outside factors such as genetics, and free will is an illusion necessary to maintain social order. Though suggestions are given for moderating impulsive behavior—especially for managing the overeating impulse—Lewis concentrates more on explaining impulses than suggesting ways to change behavior or implement reflective thinking.