I remember when girls weren't encouraged to display their intelligence. They were taught to play dumb and let the boys think they're smarter. There was even a poem, from about my grandmother's day, I think. I'll look it up. It's about a one-room school having a spelling bee, and a girl wins, and it hurts the boy's feelings. So, since she has a crush on him, she feels the need to *apologize* to him for spelling the word that he couldn't spell!

Poem here.

Edit: More like my great-grandmother's day. It's from the 1890's. But society being this way could help explain why my grandmother didn't like for me to appear too smart.