Following up on my personal favorite post.
Roughly speaking, your Shadow is the personification of your repressed awareness of the difference between your self-serving narratives and hard realities. Just as everyone has developed some defensive social coping mechanisms that are neither ideal nor realistic, everyone has self-serving narratives.
Accommodating the difference between these narratives and hard realities (the Shadow) would mean becoming aware of hard realities, destroying your narratives, and reforming your identity (i.e. new narratives) around the hard realities. Generally, this leads to dark triad behavior, e.g. PUA, propaganda, Machiavellianism, etc.
Assimilating the difference means becoming aware of hard realities, but also realizing that the ideals were simply a childish caricature of something actually good (i.e. every good lie contains an important truth), therefore holding judgment of your identity in abeyance, and rebuilding the narratives again from the realities. Generally, this leads to prosocial behavior.
One of the easiest examples is if a person has a self-concept of having a low time preference. This is conceited, since every baby is born with very high time preference. The hard reality part is realizing that all humans are fundamentally high time preference. People who lose their future orientation due to circumstances (e.g. the poverty cycle) often have a difficult time acquiring it again, because it was built on a useful fiction that was dispelled. The important truth contained in the caricatured self-concept of a responsible, high-functioning person is that low time preference is good, and some “fundamentally high time preference” people pull it off somehow. The trick to rebuilding low time preference is to realize it’s in effect a useful addiction, originally built through a painstaking social learning process. Therefore, assimilating the Shadow, in this example, means purposefully using your fundamental high time preference to addict yourself to the short-term rewards of long-term thinking.
If you can make yourself habitually anxious about the long-term consequences of bad decisions and habitually self-gratified by making good decisions, you’ve succeeded in rebuilding your low time preference from the more realistic foundation. Naturally, this process repeats until you reach the full-resolution ideal picture of a perfect person (i.e. forever) or until you cease growing as a person and begin stagnating instead.