Sometimes referred to as the "objective psyche," the collective unconscious refers to the idea that a segment of the deepest unconscious mind is genetically inherited and not shaped by personal experience. This notion was originally defined by psychoanalyst Carl Jung.

According to Jung's teachings, the collective unconscious is common to all human beings. Jung also believed that the collective unconscious is responsible for a number of deep-seated beliefs and instincts, such as spirituality, sexual behavior, and life and death instincts.

Born in Switzerland in 1875, Carl Jung founded the school of analytical psychology. He is responsible for proposing and developing the psychological concepts of the collective unconscious, along with introverted and extroverted personalities.

Jung worked with Sigmund Freud, another prominent psychologist during that time. In his early studies, Jung's work affirmed many of Freud's ideas. But as time went on, the two eventually split in their principles of psychology—including their thoughts about the development of the unconscious mind.

The biggest difference between their explanations of the unconscious mind is that Freud believed that it was the product of personal experiences, while Jung believed that the unconscious was inherited from the past collective experience of humanity.

According to Jung, the collective unconscious is made up of a collection of knowledge and imagery that every person is born with and is shared by all human beings due to ancestral experience. Though humans may not know what thoughts and images are in their collective unconscious, it is thought that in moments of crisis, the psyche can tap into it.

Understanding Jung's beliefs of the collective unconscious also require understanding the concepts surrounding these beliefs.

Jung believed that the collective unconscious is expressed through universal archetypes. Archetypes are signs, symbols, or patterns of thinking and/or behaving that are inherited from our ancestors.

According to Jung, these mythological images or cultural symbols are not static or fixed. Instead, many different archetypes may overlap or combine at any given time. Some common archetypes that Jung proposed for explaining the unconscious mind include:

In his book "Four Archetypes," Jung shared the archetypes he considered to be fundamental to a person's psychological makeup: mother, rebirth, spirit, and trickster.

Jung was convinced that the similarity and universality of world religions pointed to religion as a manifestation of the collective unconscious. Thus, deep-seated beliefs regarding spirituality are explained as partially due to the genetically-inherited unconscious.

Similarly, morals, ethics, and concepts of fairness or right and wrong could be explained in the same way, with the collective unconscious as partially responsible.

Jung used his theory of the collective unconscious to explain how fears and social phobias can manifest in children and adults for no apparent reason. Fear of the dark, loud sounds, bridges, or blood may all be rooted in this collective unconscious due to an inherited genetic trait.

In support of this, research indicates that some children are afraid of the dark not because of a negative experience they've had during the nighttime, but because darkness activates an exaggerated response by the amygdala—the part of the brain associated with the processing of emotions—resulting in the development of an innate or unprovoked fear.

Dreams were thought to provide key insight into the collective unconscious. Jung believed that due to the archetypes represented, specific symbols in dreams are universal. In other words, the same symbols mean similar things to different people.

At the same time, Jung believed that dreams are highly personal and that dream interpretation requires knowing a great deal about the individual dreamer. Freud, on the other hand, often suggested that specific symbols represent specific unconscious thoughts.

More than just being repressed wishes, Jung felt that dreams compensate for parts of the psyche that are underdeveloped in our waking lives. This has allowed for the study of dreams as an instrument for research, diagnosis, and treatment for psychological conditions and phobias.

Historically, there has been some debate around whether the collective unconscious requires a literal or symbolic interpretation.

In scientific circles, a literal interpretation of the collective unconscious is thought to be a pseudoscientific theory. This is because it is difficult to scientifically prove that images of mythology and other cultural symbols are inherited and present at birth.

Conversely, a symbolic interpretation of the collective unconscious is thought to have some scientific grounding because of the belief that all humans share certain behavioral dispositions.

Researchers are continuously trying to increase their understanding of the collective unconscious. For instance, a 2015 study suggests that the gut microbiome may play a role in how the unconscious regulates behavior. If so, studies of gut microbes could be a part of the future of psychiatric research.

Another example is a 2022 study published in Digital Geography and Society that investigates the role that the collective unconscious may play in our thoughts and behaviors while interacting on social media platforms. Thus, Jung's ideas continue to be assessed to better understand the collective unconscious and how it works.