Emerging adults in America: Coming of age in the 21st century.

By Jeffrey Jensen Arnett and Jennifer Lynn Tanner (Eds.) Washington, DC: American Psychological Association, 2006. 341 pp. ISBN 1-59147-329-2. $79.95Reviewed by Judith L. Gibbons Brien K. Ashdown What do laboratory rats, men, and college students have in common? They have often been studied by psychologists as representatives of a larger group, such as nonhuman animals or people in general. More recently, psychologists have turned to studying the species-typical behavior of rats and the roles and behavior of men and boys with respect to their masculine gender. Likewise, college students have served psychologists as representatives of humanity in studies of cognition and social and emotional behavior, but they…