The power of us Harnessing our shared identities to improve performance, increase cooperation, and promote social harmony

Psychologists Packer and Van Bavel explore "how the groups that people belong to become part of their sense of self" in this thought-provoking debut. Identities that come from groups--such as college alma maters and political parties--can influence how one makes sense of the world, the authors write: the way one sees, smells, tastes, and even does math is affected by the "identity colored glasses" one wears. Packer and Van Bavel use a variety of quirky examples and historical vignettes to make their point: in Herzogenaurach, a southern German town, citizens have defined themselves by the shoes they wear, and John F. Kennedy's decision-making process to move forward with the Bay of Pigs Invasion was a result of groupthink. Giving equal time to the detriments of identifying strongly with a group (such as political polarization and blind loyalty), as well as the benefits (solidarity and a shared sense of purpose), Packer and Van Bavel deliver a balanced assessment of the potential impacts identities play in even the most mundane activities. Providing a wealth of insight in a page-turning package, this timely survey hits the mark. Agent: Jim Levine, Levine Greenberg Rostan. (Sept.)