Bling-Bling Barbies and pouty-lipped Bratz. Thongs for tweens, and makeover parties for 5-year-olds. The past couple of shopping seasons have brought a constant stream of media stories — and books and school lectures and anguished mom conversations — all decrying the increasingly tarted-up world of young girls and preteens. Now the American Psychological Association has weighed in as well, with a 67-page report on the dangers of the “sexualization” of girls.

The report takes aim at…