In her 2006 book, Generation Me, Twenge notes that self-esteem in children began rising sharply around 1980, and hasn’t stopped since. By 1999, according to one survey, 91 percent of teens described themselves as responsible, 74 percent as physically attractive, and 79 percent as very intelligent. (More than 40 percent of teens also expected that they would be earning $75,000 a year or more by age 30; the median salary made by a 30-year-old was $27,000 that year.) Twenge attributes the shift to broad changes in parenting styles and teaching methods, in response to the growing belief that children should always feel good about themselves, no matter what. As the years have passed, efforts to boost self-esteem—and to decouple it from performance—have become widespread.
— How a New Jobless Era Will Transform America (a great overall article, but for this brief quote, paraphrasing this book)