Mike Coppola, FilmMagic | Arnaldo Magnani, Getty Images | Michael Kovac, FilmMagic

Do you think you're pushing the edge of acceptibility by wearing a mini skirt in your 40s?

Think not -- it seems nine out of ten women dress younger than their years and what's more, over half don't plan to dress "their age" until their in their 70s.

Debenhams, a department store chain in the U.K. surveyed women of all ages and found these astounding facts.

Interestingly, the younger the woman surveyed, the more likely she admitted to dressing to look older, first to impress boys and get into over-21 establishments and then in their 20s, to be taken seriously in their chosen careers.

It's in womens' 30s that the backward flow starts. More than 50 percent admitted to dressing younger in their 30s and 90 percent of women in their 40s try to pull the wool/Lycra blend over our eyes when it comes to dressing youthfully.

The list of age defiant women runs the gamut from Helen Mirren, 65, to Jane Fonda, 73, who recently wore a miniskirt to promote her new workout DVDs.

Unfortunately, these women may be more the exception than the rule. Charla Krupp, author of
"How Not to Look Old," doesn't agree with the survey.

"I find that most people are dressing more maturely in mom jeans and comfy shoes with hair styles they've had since high school," she told StyleList. "Then there are women who think they can fit into their daughter's clothes -- they look ridiculous."

Krupp cited Oprah Winfrey, Queen Latifah and Demi Moore as women who dress well, and youthfully. "Demi especially wears things that are appropriate for her age -- you don't see her in the kind of crotch-high minis and things that Jennifer Aniston wears."

In related news, check out this roundup of celebs who don't dress their age.