When the obstetrician asks if we want to know the sex of our unborn child - or children, if it's twins or more - a resounding 70% of American parents say "yes!" Let's all thank them for making baby shower planning and baby gift shopping 100% easier. Pink for girls, blue for boys. Wrap it up. By the way, did you ever wonder why these two particular colors represent the two genders?

While pink and blue appear to be logically significant to us because they've been the official "girl and boy" colors ever since we can remember, the two colors could just as easily be yellow for girls and green for boys, right? How did we wind up with pink and blue? There's actually a very interesting history behind our assigning color to gender.

In ancient times, people believed that evil spirits menaced the safety and health of infants. They also believed that these evil spirits were allergic to certain colors, especially blue. As the color of the heavenly sky, blue was thought to render satanic forces powerless and drive them away. Even today, Middle Eastern Arabs paint the doors of their homes blue to frighten away demons. The wearing of blue by a young child was not just adornment but a necessary precaution. But since female babies were considered inferior, the ancients felt they needed no special color to protect them.

For centuries, all European children were dressed in blue because of its association with the Virgin Mary. The use of pink and blue actually dawned at the turn of the century (1900) with - and this is irony at its purest - pink for boys and blue for girls, with the common belief that pink was a stronger color more suited for boys while blue was more delicate and dainty and best for girls. Contemporary color psychology actually confirms these associations. Blue is considered a calm, passive hue and consequently a feminine color. Red (and pink is derived from red) is considered intense and active, which more accurately describes boys. So what happened?

Here's where it really gets interesting. Many believe the switch happened around World War II, and it's entirely possible NAZI Germany had a hand in it. European Catholics still held a strong association with the color blue and the Virgin Mary's robes. At the same time, the NAZIs used a system of color coding for identification: Jews (yellow); criminals (green); political prisoners (red); alcoholics, the mentally retarded, vagrants, lesbians, prostitutes and anarchists (black); homosexual and bisexual men (pink).

This association of femininity with the color pink might have given rise in the 1950s to pink for girls and blue for boys. Pink also symbolizes love, fidelity, friendship, honor, harmony, compassion and faithfulness - once thought to be attributes admired among males but now the priority of females. Blue, now a male color, is considered the second most powerful color after red, and blue is the color of constancy and faith, among many other often contradictory meanings.

Today, color-coding of genders is deeply rooted - pink for girls and blue for boys - especially in the United States, where the colors for baby shower favors, decorations and baby gifts are almost always selected to reflect the gender of the baby. When you see a newborn in a passing stroller or a mother's arms, and it's impossible to tell from the face and hair (or lack of it!) whether baby is a boy or a girl, the color of the clothes or the blanket almost always give it away.