Английский Этимологический словарь - twit (v.)

- O.E. жtwitan "to blame, reproach," from жt "at" + witan "to blame," from P.Gmc. *witanan. The noun meaning "foolish, stupid and ineffectual person" is first attested 1934 in British slang, popular 1950s-60s, crossed over to U.S. with British sitcoms. It probably developed from the verb sense of "reproach" but may be influenced by nitwit.