I predict it will come to be seen as a turning point in the history of psychology. - Steven Pinker

To a linguist, the phenomenon is familiar: the euphemism treadmill. People invent new "polite" words to refer to emotionally laden or distasteful things, but the euphemism becomes tainted by association and the new one that must be found acquires its own negative connotations. "Water closet" becomes "toilet" (originally a term for any body care, as in "toilet kit"), which becomes "bathroom," which becomes "rest room," which becomes "lavatory." … The euphemism treadmill shows that concepts, not words, are in charge. Give a concept a new name, and the name becomes colored by the concept; the concept does not become freshened by the name. (We will know we have achieved equality and mutual respect when names for minorities stay put.)

The human brain is an exquisitely complex organ that evolved only once. The elephant's trunk, which can stack logs, uproot trees, pick up a dime, remove thorns, powder the elephant with dust, siphon water, serve as a snorkel, and scribble with a pencil, is another complex organ that evolved only once.

According to a recent study of the brains of identical and fraternal twins, differences in the amount of gray matter in the frontal lobes are not only genetically influenced but are significantly correlated with differences in intelligence.