observational studies reporting little or no relationship between physical activity and television viewing (Robinson and Killen, 1995; Robinson et al., 1993; Durant et al., 1994).

A second hypothesis links television viewing, in particular, to increased caloric intake either from eating during viewing or as a result of food advertising on television, which tends to emphasize high-calorie, high-fat foods with poor nutritional content (Story and Faulker, 1990). There is some evidence that amount of television viewing is related to children’s requests for, and parental purchases of, highly advertised foods (Taras et al., 1989) and that television advertising may produce incorrect nutritional beliefs in children (Ross et al., 1981). There is also experimental evidence that there are direct effects of exposure to advertising for high-calorie foods on children’s snack choices and consumption (Gorn and Goldberg, 1982; Ross et al., 1981).

Effects of Sexual Messages and Sexual Content. Throughout childhood, adolescence, and young adulthood, people continually learn more about sex, with media being a major source of information (Brown et al., 2002; Dorr and Kunkel, 1990; Wartella et al., 1990). The average child will have viewed over 14,000 sexual simulations and sexual innuendos each year (Derkson and Strasburger, 1994). Experimental studies conducted largely with convenience samples of white, middle-class young adults (often college students) have documented negative effects of nonviolent but dehumanizing pornography, especially on attitudes toward women (Kenrick et al., 1989; McKenzie-Mohr and Zanna, 1990; Weaver et al., 1984). However, the evidence is particularly disturbing in the case of violent pornography. Two major reviews of the literature, one using meta-analytic techniques (Allen et al., 1995a) and the other a conceptual review (Malamuth and Impett, 2001), both conclude that sexual violence has been found to be arousing to sex offenders, force-oriented men, and sometimes even to “normal” young men if the woman is portrayed as being aroused by the assault.

Media Use, Cognitive Development, and Academic Skills. Theory and popular perception have proposed that because television viewing involves so little mental effort, it retards cognitive development and the development of such academic skills as reading (Healy, 1990; Winn, 1985). In the case of television, there is a large body of theory and empirical data showing that both the content and form of television programs affect children’s intellectual development and social behavior (Huston and Wright, 1997). Longitudinal studies have found that watching general-audience entertainment programming can have deleterious consequences on both academic and social outcomes (Anderson et al., 2001; Friedrich-Cofer and Huston, 1986; Huesmann and Eron, 1986). But both field experiments and longitudinal studies indicate that watching educational programming in early childhood is positively related to cognitive skills (Ball and Bogatz, 1970; Rice et al., 1990; Zill, 2000), school readiness (Wright et al., 2000),

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