tested age as a moderator. Of these, five found age to be a nonsignificant moderator, one found a larger relationship of television viewing to adiposity in children ages 9 to 18 years than in children ages 5 to 8 years (Gray and Smith, 2003), and one found a larger relationship in 8-year-olds than in 12-year-olds (Maffeis et al., 1998). In other words, although there is a consistent relationship indicating that advertising exposure, as measured by amount of television viewing, is associated with adiposity in children, there is no evidence that this relationship is consistently moderated by age. This conclusion is consistent with that of the systematic evidence review.
In nearly all the studies considered above, tests of age as a moderator have not been theoretically motivated. In particular, none of the studies have considered the possibility that understanding of the persuasive intent behind advertising may be important. In general, of course, such understanding would be less in younger children. As discussed below, the most appropriate comparisons would consider children younger and older than age 8 years in order to test the premise that understanding of persuasive intent may be an important moderator of advertising effects.
Related to the moderator of age, but worthy of separate mention is the issue of the understanding of persuasive intent. This topic has been a part of public policy discussions about the legitimacy of advertising to children. At what point do children perceive advertising as a message category that is separate and distinct from television programming? When do they begin to apply a degree of skepticism to their understanding of advertising claims and appeals? Researchers have examined age-related developmental differences in children’s comprehension of the nature and purpose of television advertising quite extensively, affording strong confidence in the conclusions that can be drawn across studies.
Children must acquire two basic information processing skills to achieve mature comprehension of advertising messages: capacity to discriminate commercial from noncommercial content and ability to attribute persuasive intent to advertising, adjusting their interpretation of commercial messages accordingly (Gunter et al., 2005; John, 1999; Kunkel, 2001; Young, 1990). Each of these capabilities develops over time, as a result of cognitive growth and development more than the accumulation of exposure to media content (Kunkel, 2001).
Estimates of the age at which children can consistently discriminate advertisements as separate and distinct from adjacent programming range