Vacuousness is a quality of being mindless or unintelligent. You get a kick out of reality TV shows, but your intellectual sister scoffs at their vacuousness.
Things that demonstrate empty-headedness or a lack of deep thought are vacuous, and the state of being vacuous is vacuousness. You can use this word to express the superficiality of things (or people), like the vacuousness of middle school gossip or the vacuousness of a politician's empty words. The Latin root, vacuus, means "empty, void, or free."