I imagine that the intelligent people are the ones so intelligent that they don't even need or want to look 'intelligent' anymore.
Just as some people may conceal their own sinfulness thus seeming better than the norm, others expose their own sinfulness thus seeming worse than the norm.
She was heartily ashamed of her ignorance - a misplaced shame. Where people wish to attach, they should always be ignorant. To come with a well−informed mind is to come with an inability of administering to the vanity of others, which a sensible person would always wish to avoid. A woman especially, if she have the misfortune of knowing anything, should conceal it as well as she can.