Synchronicity is the experience of two or more events as meaningfully related, where they are unlikely to be causally related. The subject sees it as a meaningful coincidence. The concept of synchronicity was first described by Carl Jung, a Swiss psychologist, in the 1920s.
The concept does not question, or compete with, the notion of causality (however critics state that the causality, statistics and probability theorems, is enough for explaining cases of “synchronicity”, which are in fact “normal events of low probability”). It maintains that just as events may be connected by a causal line, they may also be connected by meaning. A grouping of events by meaning need not have an explanation in terms of a concrete sense of cause and effect.
In his essay, Synchronicity: An Acausal Connecting Principle, Jung writes:
…it is impossible, with our present resources, to explain ESP, or the fact of meaningful coincidence, as a phenomenon of energy. This makes an end of the causal explanation as well, for “effect” cannot be understood as anything except a phenomenon of energy. Therefore it cannot be a question of cause and effect, but of a falling together in time, a kind of simultaneity. Because of this quality of simultaneity, I have picked on the term “synchronicity” to designate a hypothetical factor equal in rank to causality as a principle of explanation.
Jung coined the word to describe what he called “temporally coincident occurrences of acausal events.” Jung variously described synchronicity as an “acausal connecting (togetherness) principle”, “meaningful coincidence” and “acausal parallelism”. Jung introduced the concept as early as the 1920s, but gave a full statement of it only in 1951 in an Eranos lecture and in 1952, published a paper, Synchronizität als ein Prinzip akausaler Zusammenhänge (Synchronicity – An Acausal Connecting Principle), in a volume with a related study by the physicist (and Nobel laureate) Wolfgang Pauli.
It was a principle that Jung felt gave conclusive evidence for his concepts of archetypes and the collective unconscious, in that it was descriptive of a governing dynamic that underlies the whole of human experience and history – social, emotional, psychological, and spiritual. Concurrent events that first appear to be coincidental but later turn out to be causally related are termed incoincident.
Jung believed that many experiences that are coincidences due to chance in terms of causality suggested the manifestation of parallel events or circumstances in terms of meaning, reflecting this governing dynamic.
Even at Jung’s presentation of his work on synchronicity in 1951 at an Eranos lecture, his ideas on synchronicity were evolving. Following discussions with both Albert Einstein and Wolfgang Pauli, Jung believed that there were parallels between synchronicity and aspects of relativity theory and quantum mechanics. Jung was transfixed by the idea that life was not a series of random events but rather an expression of a deeper order, which he and Pauli referred to as Unus mundus. This deeper order led to the insights that a person was both embedded in an orderly framework and was the focus of that orderly framework and that the realisation of this was more than just an intellectual exercise, but also had elements of a spiritual awakening. From the religious perspective, synchronicity shares similar characteristics of an “intervention of grace”. Jung also believed that in a person’s life, synchronicity served a role similar to that of dreams, with the purpose of shifting a person’s egocentric conscious thinking to greater wholeness.
A close associate of Jung, Marie-Louise von Franz, stated towards the end of her life that the concept of synchronicity must now be worked on by a new generation of researchers. For example, in the years since the publication of Jung’s work on synchronicity, some writers largely sympathetic to Jung’s approach have taken issue with certain aspects of his theory, including the question of how frequently synchronicity occurs.
One of Jung’s favourite quotes on synchronicity was from Through the Looking-Glass by Lewis Carroll, in which the White Queen says to Alice: “It’s a poor sort of memory that only works backwards.”
‘The rule is, jam to-morrow and jam yesterday — but never jam to-day.’
‘It MUST come sometimes to “jam to-day,”‘ Alice objected.
‘No, it can’t,’ said the Queen. ‘It’s jam every OTHER day: to-day isn’t any OTHER day, you know.’
‘I don’t understand you,’ said Alice. ‘It’s dreadfully confusing!’
‘That’s the effect of living backwards,’ the Queen said kindly: ‘it always makes one a little giddy at first —’
‘Living backwards!’ Alice repeated in great astonishment. ‘I never heard of such a thing!’
‘— but there’s one great advantage in it, that one’s memory works both ways.’
‘I’m sure MINE only works one way,’ Alice remarked. ‘I can’t remember things before they happen.’
‘It’s a poor sort of memory that only works backwards,’ the Queen remarked.
In his book Synchronicity (1952), Jung tells the following story as an example of a synchronistic event:
My example concerns a young woman patient who, in spite of efforts made on both sides, proved to be psychologically inaccessible. The difficulty lay in the fact that she always knew better about everything. Her excellent education had provided her with a weapon ideally suited to this purpose, namely a highly polished Cartesian rationalism with an impeccably “geometrical” idea of reality. After several fruitless attempts to sweeten her rationalism with a somewhat more human understanding, I had to confine myself to the hope that something unexpected and irrational would turn up, something that would burst the intellectual retort into which she had sealed herself. Well, I was sitting opposite her one day, with my back to the window, listening to her flow of rhetoric. She had had an impressive dream the night before, in which someone had given her a golden scarab — a costly piece of jewellery. While she was still telling me this dream, I heard something behind me gently tapping on the window. I turned round and saw that it was a fairly large flying insect that was knocking against the window-pane from outside in the obvious effort to get into the dark room. This seemed to me very strange. I opened the window immediately and caught the insect in the air as it flew in. It was a scarabaeid beetle, or common rose-chafer (Cetonia aurata), whose gold-green colour most nearly resembles that of a golden scarab. I handed the beetle to my patient with the words, “Here is your scarab.” This experience punctured the desired hole in her rationalism and broke the ice of her intellectual resistance. The treatment could now be continued with satisfactory results.
The French writer Émile Deschamps claims in his memoirs that, in 1805, he was treated to some plum pudding by a stranger named Monsieur de Fontgibu. Ten years later, the writer encountered plum pudding on the menu of a Paris restaurant and wanted to order some, but the waiter told him that the last dish had already been served to another customer, who turned out to be de Fontgibu. Many years later, in 1832, Deschamps was at a dinner and once again ordered plum pudding. He recalled the earlier incident and told his friends that only de Fontgibu was missing to make the setting complete – and in the same instant, the now senile de Fontgibu entered the room.
Jung wrote, after describing some examples, “When coincidences pile up in this way, one cannot help being impressed by them – for the greater the number of terms in such a series, or the more unusual its character, the more improbable it becomes.”
In his book Thirty Years That Shook Physics – The Story of Quantum Theory (1966), George Gamow writes about Wolfgang Pauli, who was apparently considered a person particularly associated with synchronicity events. Gamow whimsically refers to the “Pauli effect“, a mysterious phenomenon which is not, and probably never will, be understood on a purely materialistic basis. The following anecdote is told:
It is well known that theoretical physicists cannot handle experimental equipment; it breaks whenever they touch it. Pauli was such a good theoretical physicist that something usually broke in the lab whenever he merely stepped across the threshold. A mysterious event that did not seem at first to be connected with Pauli’s presence once occurred in Professor J. Franck’s laboratory in Göttingen. Early one afternoon, without apparent cause, a complicated apparatus for the study of atomic phenomena collapsed. Franck wrote humorously about this to Pauli at his Zürich address and, after some delay, received an answer in an envelope with a Danish stamp. Pauli wrote that he had gone to visit Bohr and at the time of the mishap in Franck’s laboratory his train was stopped for a few minutes at the Göttingen railroad station. You may believe this anecdote or not, but there are many other observations concerning the reality of the Pauli Effect! 
Among some psychologists, Jung’s works, such as The Interpretation of Nature and the Psyche, were received as problematic. Fritz Levi, in his 1952 review in Neue Schweizer Rundschau (New Swiss Observations), critiqued Jung’s theory of synchronicity as vague in determinability of synchronistic events, saying that Jung never specifically explained his rejection of “magic causality” to which such an acausal principle as synchronicity would be related. He also questioned the theory’s usefulness.
In psychology and cognitive science, confirmation bias is a tendency to search for or interpret new information in a way that confirms one’s preconceptions, and avoids information and interpretations that contradict prior beliefs. It is a type of cognitive bias and represents an error of inductive inference, or is a form of selection bias toward confirmation of the hypothesis under study, or disconfirmation of an alternative hypothesis. Confirmation bias is of interest in the teaching of critical thinking, as the skill is misused if rigorous critical scrutiny is applied only to evidence that challenges a preconceived idea, but not to evidence that supports it.
Likewise, in psychology and sociology, the term apophenia is used for the apparent detection of a pattern or meaning, in what is actually random or meaningless data. Skeptics, such as Robert Todd Carroll of the Skeptic’s Dictionary, argue that the perception of synchronicity is better explained as apophenia. Primates use pattern detection in their form of intelligence, and this can lead to erroneous identification of non-existent patterns. A famous example of this is the fact that human face recognition is so robust, and based on such a basic archetype (essentially two dots and a line contained in a circle), that human beings are very prone to identify faces in random data all through their environment, like the “man in the moon”, or faces in wood grain, an example of the visual form of apophenia known as pareidolia.
- Confirmation bias
- Selection bias
- Look-elsewhere effect
- Leibniz’s monadology as an assault on rationality
- Multiple discovery
- Pratītyasamutpāda (Buddhist notion of interdependent co-arising)
- Post hoc ergo propter hoc
- Superluminal communication
- Paul Kammerer, seriality theory