atavisms

Noun

atavism (countable and uncountable, plural atavisms)

1. The reappearance of an ancestral characteristic in an organism after several generations of absence; a throwback.
   • He was a magnificent atavism, a man so purely primitive that he was of the type that came into the world before the development of the moral nature. He was not immoral, but merely unmoral.1904, Jack London, chapter 10, in The Sea-Wolf (Macmillan’s Standard Library), New York, N.Y.: Grosset & Dunlap, →OCLC
2. The recurrence or reversion to a past behaviour, method, characteristic or style after a long period of absence.
   • She had lost the power to care about his faults. Strange, sweet, poisonous indifference! She was drugged. And she knew it. Would she ever wake out of her dark, warm coma? She shuddered, and hoped not. Mrs Tuke would say atavism. Atavism! The word recurred curiously.1920, D[avid] H[erbert] Lawrence, “The Wedded Wife”, in The Lost Girl, London: Martin Secker […], →OCLC, page 316
3. A reversion to past primitive behavior, especially violence.
   • I have even read in a book of criminology that the tramp is an atavism, a throw-back to the nomadic stage of humanity.1933 January 9, George Orwell [pseudonym; Eric Arthur Blair], chapter XXXVI, in Down and Out in Paris and London, London: Victor Gollancz […], →OCLC