Gender Essentialism Explained

I've decided I need to explain what I mean by "gender essentialism" to those of you who haven't heard the term before. Gender essentialism is simply the idea that there are certain personality traits/behavioral traits that are essential to one sex or the other. This belief system often inspires binary ideas about gender (either/or instead of both/and) and disappears any information that doesn't support it. It is the belief system that supports the notion that "girls are bad at math and science" or that "boys aren't interested in emotional connection". These are great big sweeping generalizations that:
1. might have some truth with some individuals but don't capture the vast range of diversity within the group "girls" or "boys"
and
2. are often credited to biological and nuerological differences, instead of the mountain of gender programming we all receive from in utero
Here is a link that discusses this issue with a keener eye turned toward challenging gender essentialism. To be sure, when we practice gender essentialism, we are enforcing strict gender rules. When we break these gender rules there are often varying degrees of punishment in the form of shunning, teasing, shaming and violence (depending on the rule that's been broken and who is witnessing the infraction). Whenever a person feels a "boys are X" observation coming on (or "girls do Y") they might practice putting that statement in the context of race. When we generalize along race lines, we call that racism. Leave comments with examples you've seen of gender essentialism in your life (either as a recipient of such gross over generalizations or as a rules enforcer).
Here's one (of many) of mine:
Back when I was first a mom and J was a wee 3 years old, I was in Sebastopol Hardware looking for a pair of winter rainboots for him. Now, I considered myself a total feminist and planned to raise J with that consciousness. He picked out a pair of purple boots. I balked. I was worried what "others" would think (boys shouldn't like X, the punishment for that will be teasing etc.). I told him there were none in his size. I came home stunned at my fear. I never realized how internalized those gender norms had become. Insidious, they were.

For moms of boys, (and really anyone could benefit from reading it) there is a book that transformed my feeling about gender rules and how they affect our boys. It's called "The Courage to Raise Good Men" and it's fabulous.
Edited to add a title