Jung’s collective unconscious is heavily misunderstood. It’s not
quackery; it’s based on the assertion that there are biological or
memetic imperatives that have been passed down from generation to
generation, and also parts of the unconscious mind that function in a
way that are common between people.
One can argue about Jung’s
implementation, especially about whether or not the archetypes he
identified are accurate and meaningful, but there seems to be a very
concrete provable fact here: the psychology of people seems to bear
commonalities, even in what would be considered extreme outliers.
whether you want to argue about the more specific cases, like those of
mythological figures appearing in unconnected contexts, Jung’s notion of
synchronicity (mutual meanings, but diverse causes) is important as
well: if dragons appear in mythology around the world, there does not
need to be a real dragon or a social connection for those things to
form. Instead, those can be independent functions of the way that people
perceive the world and form a conception of the unknown.
of the collective unconscious as this: if you put three people in a
white featureless room with a red circle painted on one wall, they will
all see the red circle and Jung would argue that they all perceive the
The value they derive from that circle comes
from the conscious mind. One person might consider it an eyesore, one
might think that it has deep symbolic meaning, and one might fear the
However, they might have associations
with the red that are common. If it were a crimson shade, it might evoke
the effect of blood.
Thus, the collective unconscious may have deep and complex elements as Jung proposed, but it almost certainly exists at least in a form as a consequence of the brain’s physiology and common formative experiences with universal human concepts (like the risk of injury).
Disclaimer: I’ve read Jung, but I’m not a master of his work. This is sort of a rambling trying to make sense of his work rather than a masterful explication of it.