MENTAL AGE • DICTIONARY ONE.COM • Definition of Mental age

... goes in casts, as garden-pots do. Lo, you! the crowd of thumb-pots; mean little tiny minds in multitudes, as near alike as possible. Then there are the frequent thirty-twos, average "clever creatures" in this mental age, wherein no one can make an ordinary how-d'ye-do acquaintance without being advertised of his or her surprising talents: and to pass by all intermediate sizes, here and there standing by himself, in all the prickly pride of an immortal aloe, some one big ...

— The Complete Prose Works of Martin Farquhar Tupper • Martin Farquhar Tupper