But where is the harm in indulging their four-year-old fantasies about manly men and girly girls? Here's my take:
1. It encourages them to judge others according to those stereotypes. Little kids are the great enforcers of the gender rules as they see them, and they can be downright cruel to kids who don't conform. When your son hears you tell someone he is "all boy", what is he supposed to think of his playmate who isn't just like him?
2. Stereotypes encourage simplistic ways of viewing a complex world. There is a reason humans use stereotypes. They help us make quick decisions in confusing or chaotic situations. But quick decisions are not always the right ones. Which serves your child better in learning to get along with other people: simple thinking or complex thinking?
3. Many of our gender stereotypes are superficial, arbitrary and subject to change. (This is the main point of my book, Pink and Blue.) Boys 100 years ago wore pink and played with dolls. Legos used to be unisex. Field hockey is a man's game in India. Elevating stereotypes to the level of natural law is, well, silly.
4. Stereotypes depend on our believing that sex and gender are binary (either-or). To summarize the last 50 years of research on the subject, they are not. There are babies born everyday who are not clearly boys or girls on the outside, and our insides -- physical, mental and emotional -- comprise an infinite range of gender identity and expressions.
Stereotypes may be cute in a four-year-old, but think of the stereotypes of teenagers, adults and elders we see in our media. How do we feel about those? Are we equally ok with our children believing in racial stereotypes? Before you let your child embrace a stereotype, think it through.