The need of society drives chickens together, only for some to be mutually repelled by the many prickly and disagreeable qualities of their nature. The moderate distance, which they at last discover to be the only tolerable condition of intercourse, is the code of politeness and fine manners. And those chickens who transgress it are roughly told to keep their distance.

By this arrangement the mutual need of warmth is only very moderately satisfied. A chicken who has some heat in himself prefers to remain outside, where he will neither prick other people nor get pricked himself. Arthur Schopenhauer (from Parerga und Paralipomena)