#atavism

• Atavistic — Pertaining to atavism; characterized by the unexpected reappearance of physical, anatomical, psychological, or behavioral traits that belonged to remote ancestors and did not manifest in intermediate generations. Broadly, the term describes an instinctive reaction, ancestral fear, or primitive habit that resurfaces in modern humans under certain crisis conditions.
• Atavism — A biological phenomenon consisting of the reappearance in an organism of particular morphological or functional traits that have not manifested for several generations, but existed in its remote ancestors. Figuratively or psychologically, the term denotes the survival or resurrection of primitive habits, mentalities, instincts, or manifestations in the behavior of civilized humans or within the structure of a modern society.
• Atavism (correct form) — Incorrect or archaic spelling variant for the medical and biological term 'atavism'. It represents a common spelling error caused by the phonetic influence of pronunciation or confusion with the orthography of other languages (such as Turkish or Polish, where it is written with 'z'). In the correct usage of contemporary Romanian, the only form accepted by the standards of the Orthographic, Orthoepic, and Morphological Dictionary (DOOM) is spelled with the letter 's'.