Synchronicity

Synchronicity is a word coined by the Swiss psychologist Carl Jung to describe the "temporally coincident occurrences of acausal events." Jung spoke of synchronicity as an "acausal connecting principle" (i.e. a pattern of connection that cannot be explained by direct causality). Plainly put, it is the experience of having two (or more) things happen coincidentally in a manner that is meaningful to the person or persons experiencing them, where that meaning suggests an underlying pattern. It differs from coincidence in that synchronicity implies not just a happenstance, but an underlying pattern or dynamic that is being expressed through meaningful relationships or events. It was a principle that Jung felt compassed his concepts of archetypes and the collective unconscious, in that it was descriptive of a governing dynamic that underlay the whole of human experience and history&mdash;social, emotional, psychological, and spiritual. Jung believed that many experiences perceived as coincidence were due not merely to chance, but instead, suggested the manifestation of parallel events or circumstances reflecting this governing dynamic.

Examples
A well-known example of synchronicity is the true story of the French writer Émile Deschamps who in 1805 was treated to some plum pudding by the stranger Monsieur de Fontgibu. Ten years later, he encountered plum pudding on the menu of a Paris restaurant, and wanted to order some, but the waiter told him the last dish had already been served to another customer, who turned out to be M. de Fontgibu. Many years later in 1832 Émile Deschamps was at a diner, and was once again offered plum pudding. He recalled the earlier incident and told his friends that only M. de Fontgibu was missing to make the setting complete - and in the same instant the now senile M. de Fontgibu entered the room.

Study
A recent study within the Princeton Engineering Anomalies Research Lab has suggested that there is a small though statistically measurable link between human thought and patterns that occur in random data sets. There is no evidence as to whether this is caused by individuals unintentionally recognizing complex patterns and then moulding their thoughts towards an unconsciously known result or the thoughts of the individual are themselves affecting the random patterns in a manner of individuation. This study's results have not been replicated, and its methodologies are disputed. 

Criticism
Since the theory of synchronicity is not testable according to the classical scientific method, it is not widely regarded as scientific at all, but rather as pseudoscientific or an example of magical thinking. However, it is doubtful that Jung would have considered the theory to be scientifically testable.

Probability theory can attempt to explain events such as the plum pudding incident in our normal world, without any interference by any universal alignment forces. However, the correct variables required for actually computing the probability cannot be found. This is not to say that synchronicity is not a good model for describing a certain kind of human experience, but, according to the scientific method, it is a reason for the refusal of the idea that synchronicity should be considered a "hard fact", i.e., an actually existing principle of our universe.

Supporters of the theory claim that since the scientific method is applicable only to those phenomena that are reproducible, independent of observer and quantifiable, the argument that synchronicity is not scientifically 'provable' should be considered a red herring, as, by definition, synchronistic events are not independent of the observer, since the observer's unique history is precisely what gives the synchronistic event meaning for the observer.

A synchronistic event appears like just another meaningless 'random' event to anyone else without the unique prior history which correlates to the event. This reasoning claims that the principle of synchronicity raises the question of the subjectivity of significance and meaning in the sequence of natural events.

Alternative explanations
The feeling of making a connection where there is none has been described as apophenia.

Aspects of the subjective experience of schizophrenia have much in common with the subjective experience of synchronicity, in the sense that ordinary events are seen as having a direct personal relevance to the schizophrenic, but are seen as 'normal' by non-schizophrenics. Many psychoses are similar to schizophrenia but can last for a very short time, such as in rare instances from nicotine withdrawal (as an example) causing the same effect even with a non-schizophrenic.

Those who have experienced a near-death experience or mystical awakenings (such as kundalini awakenings) report an increase in synchronistic events happening to them. This is also common in the study of mystical symbol systems such as Kabbalah.

A religious analogy of this experience might be attributed to the fulfillment of prayer or miracles, however Jung did not describe it in these terms.

Correlation can also be described as an 'acausal connecting principle' and so has been proposed as an analogy to the phenomenon of synchronicity. Though correlation does not necessarily imply causation, correlation may in fact be a physical property shared by events without there being a classical cause-effect relationship, as shown in quantum physics, where widely separated events can be correlated without being linked by a direct physical cause-effect (see nonlocality, EPR paradox).

Synchronicity has been proposed as a corollary phenomenon of the many-worlds or parallel universes theory of quantum physics, in that the subject is somehow 'navigating' to those particular alternate worlds that are correlated to their past history, among the myriad possible other worlds that are not as correlated to their past history.

Although this idea has made it into the popular press, it is considered pseudoscience by most scientists as the parallel universe theory states that all possible futures exist simultaneously, therefore the subject indeed lives out all possible futures in parallel.

Trivia

 * In the role playing game, d20 Modern, the supplement Urban Arcana features a spell known as 'Synchronicity', which subtly alters the laws of reality to make the mundanities of life more convenient for the caster, such as altering bus and taxi schedules so that they always appear within a maximum of four minutes after the caster begins waiting for one, and subtly moving pedestrians on crowded streets out of the way of the caster.
 * A similar effect is delivered by the Felix Felicis potion in the Harry Potter book series.
 * John Constantine, the main character in the Vertigo Comics series Hellblazer, is sometimes seen "riding the synchronicity highway," to meet certain goals or even just to one up those around him. This has the same effect as that described in this article, and it is one of John Constantine's more unique tricks, and part of what makes him so dangerous. He is also seen doing this in Books of Magic, the graphic novel by Neil Gaiman.
 * The phenomenon is also explored, though not named in "The Red Notebook" by Paul Auster.
 * In the 1983 release Synchronicity by The Police (A&M Records), bassist Sting is reading a copy of Jung's Synchronicity on the front cover along with a negative/superimposed image of the actual text of the synchronicity hypothesis. A photo on the back cover also shows a close-up but mirrored and upside-down image of the book.  There are two songs titled "Synchronicity I" and "Synchronicity II" included in the album. The latter song cleverly contrasts the dangerous breakdown of a desperate family man with the simultaneous emergence of a menacing creature from the bottom of Loch Ness.
 * In the 1976 film The Eagle Has Landed, the character Max Radl (Robert Duvall) asks a subordinate if he is familiar with the works of Jung, and then explains the theory of Synchronicity. He also tells a cautionary tale of not reading too much into supposed synchronicity, commenting that "a wink from a pretty girl at a party rarely results in climax...but a man is a fool not to push a suggestion as far as it will go!"
 * The Dirk Gently series of books by Douglas Adams often plays on the synchronicity concept. The main character carries a "pocket I Ching" that also functions as a calculator, up to a point.
 * The concept of ta'veren in Robert Jordan's The Wheel of Time series functions similarly to synchronicity.