Origin and history of wrong-headed

Middle English hed, from Old English heafod "top of the body," also "upper end of a slope," also "chief person, leader, ruler; capital city," from Proto-Germanic *haubid (source also of Old Saxon hobid, Old Norse hofuð, Old Frisian haved, Middle Dutch hovet, Dutch hoofd, Old High German houbit, German Haupt, Gothic haubiþ "head"), from PIE root *kaput- "head."

Modern spelling is early 15c., representing what was then a long vowel (as in heat) and remained after pronunciation shifted. Of rounded tops of plants from late 14c. The meaning "origin of a river" is mid-14c. The meaning "obverse of a coin" (the side with the portrait) is from 1680s; meaning "foam on a mug of beer" is attested by 1540s; meaning "toilet" is from 1748, based on location of crew toilet in the bow (or head) of a ship.

Synecdochic use for "person" (as in head count) is attested by late 13c.; of cattle, etc., in this sense from 1510s. As a height measure of persons, from c. 1300. Meaning "drug addict" (usually in a compound with the preferred drug as the first element) is from 1911.

To be over (one's) head "beyond one's comprehension" is by 1620s. To give head "perform fellatio" is from 1950s. Phrase heads will roll "people will be punished" (1930) translates Adolf Hitler. Head case "eccentric or insane person" is from 1966. Head game "mental manipulation" attested by 1972. To put heads together "consult" is from late 14c.

late Old English, "twisted, crooked, wry" (senses now obsolete), from Old Norse rangr, earlier *vrangr "crooked, wry, wrong," from Proto-Germanic *wrang-, a nasalized variant of *wergh- "to turn," which according to Watkins is from PIE root *wer- (2) "to turn, bend."

Germanic cognates include Danish vrang "crooked, wrong," Middle Dutch wranc, Dutch wrang "sour, bitter," literally "that which distorts the mouth." Wrong thus would be etymologically a negative of right (adj.1), which is related to Latin rectus, literally "straight."*

The sense of "not right, bad, immoral, unjust, deviating from what is right or proper" developed by c. 1300. The meaning "not in accordance with reality" is by mid-14c.; of persons, "in a state of misconception or error," by early 15c. It is by mid-14c. as "less desirable or suitable" (of two).

As an adverb from c. 1200, "not rightly, incorrectly." To go wrong is in Shakespeare. Related: Wrongness; wrongish (1849).

To get up on the wrong side (of the bed) "be in a bad mood" is recorded from 1801, according to OED (1989), from its supposed influence on one's temper; it appears in Halliwell's "Dictionary of Archaic and Provincial Words" in 1846, but doesn't seem to have been used much generally before late 1870s.

To rise on the right side (of the bed) is proverbial by 1560s indicating either good luck or a good disposition. To be on the wrong side of a given age, "older than," is from 1660s. Wrong side of the road (that reserved for oncoming traffic) is by 1791. To be from (or on) the wrong side of the tracks "from the poor part of town" is from 1921, American English.

* Latin pravus was literally "crooked," but most commonly "wrong, bad;" and other words for "crooked" also have meant "wrong" in Italian and Slavic. Compare French tort "wrong, injustice," from Latin tortus "twisted."