Two studies were conducted among children 8 and 9, 12 and 13 and 16 to 18 by Deborah Roedder John, a professor of marketing at the University of Minnesota's Carlson School of Management, and Lan Nguyen Chaplin, assistant professor of marketing at the University of Illinois.

In the first study, the researchers found that materialism increases during the younger ages but declines near the end of the high school years.

"The level of materialism in teens is directly driven by self-esteem," John said. "When self-esteem drops as children enter adolescence, materialism peaks. Then, by late adolescence, when self-esteem rebounds, their materialism drops."

In the second study, the young people received paper plates with positive descriptions about them, such as "smart" and "fun," by their peers in a summer camp setting.

The study, published in the December issue of the Journal of Consumer Research, found this seemingly small gesture sharply reduced the high levels of materialism found among 12- and 13-year-olds- and the moderate levels of materialism among 16- to 18-year-olds.