Assimilation

1. Etymology

Assimilation names the process of integrating outer objects (persons, things, ideas, values) and unconscious contents into consciousness. Related: apperception; dissimilation; subject–object approximation.

2. Plain summary

Assimilation brings the new near what is already constellated in the subject—so the outer or unconscious content can join consciousness. It is a kind of apperception, but with that extra step of approximating the new to subjective material already alive.

Jung contrasts it with dissimilation: approximating the subject to the object so the person becomes alienated from themselves in favor of the object—whether an external thing or a psychological object such as an idea. Related to adaptation without being the same word.

Examples (exhaustive house list for this Index lemma — common assimilation motifs named across Jung’s essays and standard Jungian lexica; not a claim that Jung’s CW contains only these):
integrate outer objects into consciousness; integrate unconscious contents; approximation to subjective material; vs apperception (related); vs dissimilation (subject → object); alienation from self toward object; persons/things/ideas/values; Definitions ¶¶685f.

3. Academic elucidation

In analytical psychology assimilation is subject-ward integration of the new—object brought toward subject—kept distinct from dissimilation. Descent Press keeps Sharp in §4; Samuels has no dedicated head this pass. §5 holds sample CW stamps at Definitions. Prefer CW 6.

4. Lexicon

Sharp (1991)

Assimilation. The process of integrating outer objects (persons, things, ideas, values) and unconscious contents into consciousness. Assimilation is the approximation of a new content of consciousness to already constellated subjective material … Fundamentally, [it] is a process of apperception, but is distinguished … by this element of approximation to the subjective material. … I contrast dissimilation, as the approximation of subject to object…

(Sharp, 1991)

5. CW concordance — sample, not exhaustive

ASSIMILATION is the approximation of a new content of consciousness to already constellated subjective material, the similarity of the new content to this material being especially accentuated in the process, often to the detriment of its independent qualities. Fundamentally, assimilation is a process of apperception (q.v.), but is distinguished from apperception by this element of approximation to the subjective material.
(Jung, 1921/1971, CW 6, pp. 576–577, ¶685)

I use the term assimilation in a somewhat broader sense, as the approximation of object to subject in general, and with it I contrast dissimilation, as the approximation of subject to object, and a consequent alienation of the subject from himself in favour of the object, whether it be an external object or a “psychological” object, for instance an idea.
(Jung, 1921/1971, CW 6, p. 577, ¶686)

See also: apperception; consciousness; unconscious; adaptation; abstraction.

References

Jung, C. G. (1971). Psychological types [Definitions]. In H. Read, M. Fordham, G. Adler, & W. McGuire (Eds.), The collected works of C. G. Jung (R. F. C. Hull, Trans.) (Vol. 6, pp. 576–577, ¶¶685–686). Princeton University Press. (Original work published 1921)

Samuels, A., Shorter, B., & Plaut, F. (1986). A critical dictionary of Jungian analysis. Routledge.

Sharp, D. (1991). Jung lexicon: A primer of terms & concepts. Inner City Books.