The 'collective unconscious' was discussed by Carl Jung. What evidence exists that we have a collective unconscious?

The evidence  that we have on unconscious is instincts and archetypes

Explanation:

1.Archetypes:

In simple words, archetypes can be stated as an example of a  certain thing or in other words  they are the mode of apprehensionArchetypes deals with the chronology of a human life span and the stuff like evolutionaryThe example of archetypes is mother, old wise man, order, etc..,

2.  Instincts:

In simple words,  instincts  can be stated as the fixed pattern of  behavior in living organisms in response to the stimuliThey build on the classical issues in biology and psychologyHuman beings have five Humans types of like wrote Jung: hunger, sexuality, activity, reflection, and creativity.