• by Robert Passikoff , Op-Ed Contributor, March 26, 2009

You turn 50, and you lose ground to your rivals. Suddenly the wealth of houses, dream cars and your ability to get as many Ken dolls as you want mean nothing: they're out there lusting after younger dolls.

The icon that put the "plastic" in plastic surgery, Barbie remains a well-known and polarizing cultural and social phenomenon. Introduced in the pre-dawn of the feminist movement, generations of women have grown up with her wardrobes, careers, friends, boyfriends, pets, playhouses, and flashy pink sports cars. But a lot has changed in 50 years, and Mattel, which introduced Barbie five decades and a billion units ago, is rolling out a commemorative doll and promoting "All Things Barbie" to perk up sagging sales.

Barbie's history, however, has reflected the evolving role of women. For example:

• When Barbie debuted, women made up 38% of the workforce. Now they make up 60%.

• Mattel introduced an Astronaut Barbie in 1965, but it wasn't until 1983 that Sally Ride became the first U.S. woman in space.

• In 1973, Nurse Barbie went to med school. The percentage of female doctors back then? 10%. Now it's 35%.

• In 1989 Barbie served in four military branches, wearing uniforms approved by the Pentagon. The number of female veterans today numbers 1.8 million at an average age of 47.

• In 1992, Teen Talk Barbie whined, "Math class is tough," prompting anger from parents and an apology from Mattel. Still, the number of math doctorates granted to women at that time was 23%. Today it's only slightly higher, at 29%.

• In 2004, Barbie and long-time boy-toy, Ken, broke up after 43 years and then reunited in 2006, which is a real storybook ending since today only 6% of divorced couples get back together.

However, unlike real women, Barbie hasn't changed physically and it's been noted that her measurements -- at 36-18-38 -- if rendered in the flesh, would make it impossible for her to stand.

She's lost market share over the past decade, with domestic sales falling as much as 12% in recent years. And no matter what memories she evokes for moms, her target audience has grown younger, more sophisticated, and increasingly disinterested in the fantasy Barbie has to offer. What's worse, interactive dolls, toys, and video games have moved into the dream-house neighborhood.

All the categories we study change over time, and this is no exception. What was once considered edgy now seems relatively tame, especially when compared to real-life Barbies like Jessica Simpson, Lindsay Lohan and Britney Spears. More recently, she's been replaced by Bratz dolls with pouty lips and by Hannah Montana fashion-dolls.

Still and all, it's a real cultural and marketing event. Barbie, the iconic fashion doll with the top-heavy figure and high-heel arches is 50. And some fairytales do continue for girls even when women are long past the point of believing in them.