What an interesting question!!!
There are definitely some theories that are moving towards a genetic memory or ancestral memory concept. I have also read a few theories and research on past life experience which concluded that the individual's recalling past life experience may not be calling their actual past life experience but the life experience of their past ancestors. The argument was based on the science of DNA replication and how much information is actually stored with DNA and our cells. (I am obviously oversimplifying but it was interesting)
experience even across cultures is a similar one-- we all have the same basic needs, live on the same planet and can likely associate the same symbols with similar meaning.
I am a dream interpreter and have noticed this when analyzing dreams. People do seem to have a basic agreement of what certain symbols, metaphors, archetypes, etc. although I will say I am less accurate with my interpretations of dreams from a culture outside of mine. As human beings we stress and emphasize the differences across people but the possible explanation of us seeming to have a collective consciousness is that we have more in common than we tend to notice.