The American psychologist William James once said, “If you want a quality, act as if you already have it.” Wiseman (59 Seconds), a British psychologist and social media phenomenon, backs up the “act as if” dictum by parsing scientific studies and offering practical tips to help folks become the person they want to be. If you’re lacking in confidence, adopt a more powerful pose; if you’re feeling down, just smile! Drawing from such well-known trials and tests as the Zimbardo prison study and the Stanislavski acting method, as well as historical and pop culture figures like Frederick Douglass and Joan Baez, Wiseman makes a convincing argument for the power of action (though his assertion that his is a “radically new approach” is less persuasive—James uttered his famous maxim in 1884). Yet he’s at his best when he puts down his bag of tricks and turns his attention to the relationship between action and thought, as when he considers the inefficacy of public health information campaigns when compared to the success of legislation in changing behavior. Readers who have enjoyed Wiseman’s previous work will likely enjoy this addition to his oeuvre; more skeptical readers might just have to grin and bear it. Illus. (Jan.)