Synchronicity is a term created by Carl Jung, the founder of analytical psychology. It describes events that happen at the same time and seem connected in a meaningful way, even though there's no clear reason for them to be linked. Jung believed this was a normal part of the mind, but it can cause problems in serious mental illnesses like psychosis.

Jung created this idea as a way to explain how events can seem connected without a clear cause. He worked with physicist Wolfgang Pauli to develop this concept further. Together, they wrote a book in 1952 called The Interpretation of Nature and the Psyche. Their work led to the Pauli–Jung conjecture. They argued that, just as cause-and-effect relationships help explain the mind and the world, so can relationships that are not based on cause and effect.

A 2016 study found that 70% of therapists believed synchronicity experiences could help in therapy. Analytical psychologists say people must understand the meaning of these events to improve awareness and avoid superstition. However, some people who share these experiences say they are not listened to or understood. Having too many meaningful coincidences can sometimes be a sign of a mental condition like schizophrenia.

Jung used synchronicity to support the idea of the paranormal, which is the belief in events that cannot be explained by science. This idea was later discussed by Arthur Koestler in his book The Roots of Coincidence and was also adopted by the New Age movement. Unlike magical thinking, which believes unrelated events have hidden cause-and-effect links, synchronicity suggests events might be unrelated but connected in a way that is not yet understood.

From a scientific perspective, synchronicity is hard to test or prove, so it is not studied using scientific methods. Scientists often call it pseudoscience. Jung said these events are random from a statistical point of view, but they might feel meaningful because they seem to support paranormal ideas. Jung did not use scientific studies to support his ideas, but later research has been done on the topic.

Statistics and probability show that some events seem surprising but are actually common. People might think they are meaningful, but they could be due to mistakes in how we see patterns or misunderstand probabilities.

Origins

Carl Jung introduced the idea of synchronicity during a lecture in 1930, though he may have first used the term as early as 1928. He used it to describe the connection between events and inner experiences, especially when discussing ideas from Chinese philosophy. The I Ching, an ancient Chinese text, played a key role in this. It contains 64 symbols called hexagrams, each made from two smaller symbols called trigrams. People use random methods, like tossing coins, to choose a hexagram, and the text then provides guidance about a person's situation. Richard Wilhelm, a translator of the I Ching, helped Jung understand its meaning. They met in Germany, where Wilhelm shared his work with Jung. Later, in 1923, both were in Zurich, and Wilhelm spoke about the I Ching at a psychology group meeting.

The I Ching is one of the five important texts in Confucianism. By using chance methods to pick a passage, the text is believed to reveal insights about a person’s inner state. Jung saw this as an example of synchronicity and believed the text gave meaningful results in his own life. He later encouraged some of his patients to use it. Jung also found ideas about synchronicity in Chinese philosophy, especially in Taoist beliefs. He was influenced by German thinkers like Gottfried Leibniz, Arthur Schopenhauer, and Johannes Kepler. Leibniz’s study of the I Ching in the 17th century helped shape the idea of synchronicity in Western thought. Schopenhauer, in particular, wrote about events seeming to happen on purpose, which Jung saw as an early version of synchronicity.

Jung also studied the work of Paul Kammerer, who thought hidden patterns in nature could explain coincidences. In 1932, Jung began a long discussion with physicist Wolfgang Pauli about synchronicity, science, and the "Pauli effect." Jung used the idea of numinosity, a term from religious scholar Rudolf Otto, to describe the deep, meaningful feelings in religious experiences. This idea faced criticism. Jung also looked at the work of J. B. Rhine, who studied extrasensory perception in the 1930s.

Jung first clearly explained synchronicity in a major speech at an Eranos conference in 1951. The next year, he and Pauli published a book titled The Interpretation of Nature and the Psyche, which included Jung’s main essay on the topic, "Synchronicity: An Acausal Connecting Principle."

Other influences on the idea of synchronicity include religious beliefs about connections between things, practices like sympathetic magic, astrology, and alchemy.

The Pauli–Jung conjecture was a joint project between physicist Wolfgang Pauli and psychologist Carl Jung. They worked together from 1946 to 1954, exploring how mind and matter might be connected through synchronicity. Pauli used ideas from quantum theory, like complementarity and the observer effect, to support their work. Together, they suggested that the connections between events are not based on numbers, as in physics, but on meaning.

Modern physicist T. Filk notes that quantum entanglement, a type of connection between particles that happens without direct contact, may have inspired Pauli to see it as a model for how mind and matter relate, as proposed by Jung and himself. Quantum entanglement is the physical process that most closely matches the idea of synchronicity.

Analytical psychology

In analytical psychology, noticing events that seem meaningful by chance is a way for hidden thoughts to become known to the conscious mind. Whether these events lead to harm or growth depends on how the person responds to them. Jung suggested that this idea could help in mental health by reducing the harm caused by overthinking and the belief that the mind and body are separate.

Analytical psychology believes that modern ways of thinking are based on older, basic parts of the mind. Modern views often focus on cause-and-effect relationships, seeing events without clear causes as random. However, older ways of thinking see such events as intentional. Both modern and older views use different ways to explain connections: modern thinking uses cause-and-effect, while older thinking uses meaning-based connections. Both are human ways of interpreting the world. Jung believed that older ways of thinking are still important parts of the modern mind and often influence how people find meaning in life. Just as cause-and-effect helps explain events with clear reasons, the idea of meaningful chance, or synchronicity, helps explain events that seem unrelated but still have meaning. Jung considered synchronicity one of three key ideas for understanding the mind:

• Psychological causality, as described by Freud, explains how hidden energy is released in the mind based on cause and effect. Jung expanded this to include all mental energy that helps the mind grow.
• Psychological teleology refers to the idea that the mind has the potential to become fully realized.
• Psychological synchronicity describes how meaningful events that seem unrelated can help or hinder personal growth.

Jung believed that synchronicity helped explain his ideas about shared symbols and the collective unconscious. It showed how a hidden force influences all human experiences—social, emotional, mental, and spiritual. The idea of synchronicity marked a shift away from the belief that the mind and body are separate, moving toward the idea that both are parts of the same reality. Some say this change helped make Jung’s earlier ideas more consistent and clear.

Philosophy of science

Carl Jung believed that the idea of synchronicity had both philosophical and scientific reasons. He compared the relationship between cause and effect (causality) and events happening without clear cause (acausality) to ideas found in Eastern sciences and early scientific fields. He noted that Eastern traditions often rely on patterns of events that seem random but are seen as meaningful, stating, "The East bases much of its science on this irregularity and considers coincidences as the reliable basis of the world rather than causality. Synchronism is the prejudice of the East; causality is the modern prejudice of the West." (See also: universal causation.) Scholar L. K. Kerr explained that Jung focused only on one type of cause—efficient cause—so his idea of acausality was limited. This narrower view did not account for other types of causes, such as purpose or form, which are part of older systems like those of Aristotle or Thomas Aquinas. If purpose (final causality) is part of synchronicity, it could help explain personal growth. However, the idea of purpose or direction (teleology) is not widely accepted in modern science. Jung’s ideas combined mainstream scientific thinking with other perspectives, including those that differ from traditional science.

Paranormal

Carl Jung used the idea of synchronicity to argue that paranormal events exist. Modern scientists often say this approach is not based on real science. Jung's partner, Wolfgang Pauli, disagreed with Jung's questionable experiments that connected astrology to the uncertainty principle, which Jung believed was supported by laboratory research. Jung also referred to the work of parapsychologist Joseph B. Rhine to suggest a link between synchronicity and paranormal experiences. In his book Synchronicity: An Acausal Connecting Principle, Jung wrote:

Roderick Main, in the introduction to his 1997 book Jung on Synchronicity and the Paranormal, wrote:

Studies

• A 1989 summary from the Journal of the American Statistical Association discussed different ways to study coincidence and the areas of research related to synchronicity experiences.

• A 2009 study found that in clinical settings, synchronicity experiences often happen more often during times of strong emotions or major life changes, such as births, deaths, or marriages.

• A 2016 study showed that clients who shared synchronicity experiences in therapy often felt they were not heard, accepted, or understood. The study also noted that therapists sometimes found these experiences surprising and difficult to explain, leading researchers to suggest the need for clear information about synchronicity for mental health professionals.

• A 2016 study of 226 therapists found that 44% had experienced synchronicity during therapy, and 67% believed these experiences could be helpful in therapy. The study also noted that psychologists were more likely than counselors or psychotherapists to say chance was a possible explanation for synchronicity, while counselors and psychotherapists were more likely to say that the need for hidden emotions to surface could explain these experiences.

• A 2018 study showed that the idea of synchronicity is used in therapy through a specific method inspired by the psychologist Carl Jung. This approach allows therapists to use meaningful coincidences between themselves and patients to create a personal story that feels meaningful to the patient. If these moments are carefully recognized, discussed, and explained, they can improve the relationship between the therapist and patient and help the therapy process.

Scientific reception

Since they were first introduced, Carl Jung's ideas about synchronicity have been widely debated and have not gained broad support from the scientific community. Scientists who are skeptical believe these ideas are not real science. Mainstream science also does not accept explanations involving the paranormal for coincidences.

Despite this, the concept of synchronicity and experiences related to it are still studied in areas such as philosophy, cognitive science, and analytical psychology. Synchronicity is often questioned because probability theory can explain how coincidences happen, the connection between synchronicity experiences and cognitive biases, and doubts about whether the theory is helpful in psychology or science.

Fritz Levi, a psychologist who lived at the same time as Jung, criticized Jung's theory in a 1952 review published in the periodical Neue Schweizer Rundschau (New Swiss Observations). Levi said Jung's theory was unclear about how to determine if events were synchronistic. He also questioned whether the theory had any real use.

In a 1981 paper, parapsychologist Charles Tart wrote:

Robert Todd Carroll, the author of The Skeptic's Dictionary in 2003, argued that experiences of synchronicity can be better explained by apophenia—the tendency for people to see meaning in random events. He stated that over a lifetime, people may experience several coincidences that seem unpredictable, and there is no need for Jung's metaphysical explanation of these events.

In a 2014 interview, emeritus professor and statistician David J. Hand said:

In a 2015 paper, scholars M. K. Johansen and M. Osman wrote:

Scientific explanations

Several researchers have suggested ideas that try to explain synchronicity using scientific or similar-to-scientific methods. Although the idea of synchronicity is still debated and not widely accepted by most scientists, these attempts show that many fields of study are interested in understanding why people believe certain events are meaningful coincidences.

Carl Jung believed that math patterns, like the Fibonacci sequence, might be connected to synchronicity.

One idea comes from physicist Gregory S. Duane, who created a model called the chaotic oscillator. This model, described in Synchronicity from Synchronized Chaos, compares how chaos in complex systems can lead to order with Jung’s idea of events happening without a clear cause. Duane suggests that what people see as coincidences might naturally occur in systems where chaos becomes organized.

Another idea is the Pauli–Jung Conjecture, which developed from letters between Jung and physicist Wolfgang Pauli. Scholars like Atmanspacher and Fuchs (2014) have explored how ideas such as quantum entanglement and nonlocality might be used as metaphors to describe synchronicity, even though they are not direct explanations.

From the field of cognitive science, Johansen and Osman (2015) argued that people’s belief in coincidences can be explained by how the brain processes information, mental shortcuts, and the tendency to notice events that support existing beliefs. Their work suggests that experiences of synchronicity might be understood through psychology rather than being caused by unknown forces.

Although these ideas come from different areas of study and use different methods, they all aim to find ways—whether through physics, psychology, or symbols—to better understand experiences of synchronicity.

Examples

Carl Jung wrote about a special kind of event called synchronicity in his 1960 book Synchronicity. He explained that when many unusual events happen together, it is hard not to notice them. He said that the more events there are, or the more strange they seem, the less likely they are to happen by chance.

In his memoirs, French writer Émile Deschamps described an event from 1805. A stranger named Monsieur de Fontgibu gave him some plum pudding. Ten years later, Deschamps saw plum pudding on a restaurant menu in Paris. He wanted to order it, but the waiter said the last serving had already gone to another customer, who was de Fontgibu. Many years later, in 1832, Deschamps was at a dinner and ordered plum pudding again. He remembered the earlier event and told his friends that only de Fontgibu was missing to complete the scene. At that moment, de Fontgibu entered the room, though he was very old and confused and had gone to the wrong address.

In his 1966 book Thirty Years That Shook Physics: The Story of Quantum Theory, George Gamow wrote about Wolfgang Pauli, a scientist often linked to synchronicity events. Gamow playfully described the "Pauli effect," a strange phenomenon that cannot be fully explained by physical science. One story about this effect is told in the book.

In popular culture

In his 1963 science-fiction novel The Game-Players of Titan, Philip K. Dick mentioned "Pauli's synchronicity," describing how pre-cognitive abilities (the power to see the future) can be disrupted by other abilities, such as psychokinesis (the power to move objects with the mind). He called this connection between events an "acausal connective event."

In 1983, the music group The Police released an album named Synchronicity, inspired by Arthur Koestler's book The Roots of Coincidence, which discusses the concept of synchronicity. One song from the album, "Synchronicity II," tells two stories at the same time: one about a man having a mental breakdown and another about a monster rising from a Scottish lake.

The musician Björk wrote a song called "Synchronicity" for Spike Jonze's Hot Chocolate DVD.

In 2015, the band Rising Appalachia released a song titled "Synchronicity" on their album Wider Circles.