While Carl Jung's theories, particularly his concept of the collective unconscious and archetypes, provide a framework for understanding the deep-seated aspects of the human psyche, including potentially ancient elements, it would be an oversimplification to attribute the exclusive ability to access the Pleistocene or a "two-million-years-old self" solely to Jung among depth psychologists.
Jung's ideas indeed suggest that certain archetypes and psychological patterns may have roots in humanity's evolutionary past, potentially stretching back to the Pleistocene era and beyond. He proposed that the collective unconscious contains inherited, universal symbols and motifs that reflect fundamental aspects of the human experience and may have emerged over vast spans of evolutionary time.
However, other depth psychologists and psychoanalysts have also explored the connections between human psychology and evolutionary history, albeit from different theoretical perspectives. For example:
Sigmund Freud: While Freud's psychoanalytic theory differs significantly from Jung's, he also recognized the importance of evolutionary factors in shaping human behavior and psychology. Freud's theories of the unconscious, instincts, and childhood development all incorporate elements that can be understood in evolutionary terms.
Erich Neumann: A student of Jung, Neumann expanded on Jung's ideas of archetypes and the collective unconscious. Neumann explored the relationship between psychological development and cultural evolution, suggesting that certain archetypal patterns reflect the evolutionary history of the human species.
Robert Ardrey: Ardrey was not a psychologist but an influential writer who explored the intersection of human behavior and evolutionary biology. His work, particularly in books like "African Genesis" and "The Territorial Imperative," popularized the idea that human behavior is influenced by our evolutionary heritage.
Ernest Becker: Becker's work, particularly in "The Denial of Death," delves into the psychological consequences of human awareness of mortality and the ways in which this awareness shapes cultural beliefs and behaviors. While not explicitly focused on evolutionary psychology, his ideas touch on fundamental aspects of human nature that have likely been shaped by our evolutionary history.
Overall, while Jung's theories provide a framework for understanding the deep-seated aspects of the human psyche, other depth psychologists and theorists have also explored the connections between human psychology and evolutionary history. The exploration of the "two-million-years-old self" is a multifaceted endeavor that draws on insights from various disciplines, including psychology, anthropology, evolutionary biology, and cultural studies.