This somewhat represents mythology around cancer specifically.
Why does the astrology sign for Cancer seem to represent a yin and yang?
According to this
This is also seen as two crab's claws, intertwined in a way which represents the dual nature of the Cancerian personality. In this form, it would be understood as similar to the Asian Yin and Yang symbol.
Is this all there is to it?
If you read the book "Divine Love Astrology: Revealing Spiritual Truth for Personal Transformation" it briefly mentions the following.
The symbol for Cancer represents a crab's claws and also symbolizes the yin and yang or the male and the female joined in the fertilized egg.
Cancer I believe has often been viewed as very carrying so maybe this has to do with the opposing opposites of male vs female characteristics but I haven't found a source for this.
