American youth are awash in media. They have television sets in their bedrooms, personal computers in their family rooms, and digital music players and cell phones in their backpacks. They spend more time with media than any single activity other than sleeping, with the average American eight- to eighteen-year-old reporting more than six hours of daily media use. The growing phenomenon of "media multitasking"—using several media concurrently—multiplies that figure to eight and a half hours of media exposure daily. Donald Roberts and Ulla Foehr examine how both media use and media exposure vary with demographic factors such as age, race and ethnicity, and household socioeconomic status, and with psychosocial variables such as academic performance and personal adjustment. They note that media exposure begins early, increases until children begin school, drops off briefly, then climbs again to peak at almost eight hours daily among eleven- and twelve-year-olds. Television and video exposure is particularly high among African American youth. Media exposure is negatively related to indicators of socioeconomic status, but that relationship may be diminishing. Media exposure is positively related to risk-taking behaviors and is negatively related to personal adjustment and school performance. Roberts and Foehr also review evidence pointing to the existence of a digital divide—variations in access to personal computers and allied technologies by socioeconomic status and by race and ethnicity. The authors also examine how the recent emergence of digital media such as personal computers, video game consoles, and portable music players, as well as the media multitasking phenomenon they facilitate, has increased young people's exposure to media messages while leaving media use time largely unchanged. Newer media, they point out, are not displacing older media but are being used in concert with them. The authors note which young people are more or less likely to use several media concurrently and which media are more or less likely to be paired with various other media. They argue that one implication of such media multitasking is the need to reconceptualize "media exposure."