regression

Estimated CEFR level: C2 — Proficiency

Estimated from word frequency; not an official CEFR classification.

Definition

noun an abnormal state in which development has stopped prematurely
noun (psychiatry) a defense mechanism in which you flee from reality by assuming a more infantile state
noun the relation between selected values of x and observed values of y (from which the most probable value of y can be predicted for any value of x)

Learned borrowing from Latin regressio. Equivalent to regress + -ion. The statistics sense comes from regression to the mean.

Wherefore, lest we fall into an infinite regression, we must acknowledge the supreme God to be full of supreme and perfect good. — The Consolation of Philosophy, Boethius
As regards space, we must, by an effort of mind sui generis, follow the progression or rather the regression of the extra-spatial degrading itself into spatiality. — Creative Evolution, Bergson, Henri
But Tylor remarks, “I cannot but think that Dr. Martius’ deduction is the absolute reverse of the truth.” Certainly the theory of the Indians’ regression is, I consider, entirely erroneous. — The North-West Amazons: Notes of some months spent among cannibal tribes, Thomas Whiffen

arrested development, fixation, infantile fixation

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