Black Swan Theory

In 2007 Nassim Taleb, a Lebanese-American scholar and essayist on uncertainty, probability and knowledge, published “The Black Swan–The Impact of highly probable”. The book has been widely discussed, with both praises and criticisms, and describes the author’s view on rare events that deviate beyond normal expectations. According to Taleb, these events are impossible to predict through scientific methods, and may play a key role in history, similary to how the discovery at the end of the XVII century of black swans in Australia made by the Dutch explorer Willem de Vlamingh changed zoology (Latronico 2015).

Taleb defines Black Swan an event with these attributes (Taleb 2010, prologue):

 Rarity: it is not expected, as it was not conceivable

If we consider anthropometric measurements, such as weight, height, and so on, we can expect a variation among different persons. However, the values will remain in all likelihood in a limited range: for instance, the tallest adult ever measured was 247 cm tall, while the shortest man was 34 cm tall (Chivers 2009). Even if impressive, there is a clear limit in both the directions. Not every dimension vary within a limited range, though: other variables are scalable, and can imply enormous variations. For instance, personal income is in this group. Social dimensions tend to be scalar, especially if they are not tangible, but informational (Taleb 2010, p. 33). The transition from non-scalar to scalar dimensions is associated to the invention of the phonograph (Thompson 2016): before, a singer could gain only a limited amount for every exhibition, while the opportunity to record their performance made their income not bonded to the single show and scalable. All the while, this process has another consequence: previously, various musicians could play in different theatres, surviving with their profession but without becoming extremely rich; with the reproducibility of sound, all the listeners have the opportunity to buy the (perceived) best musician’s recordings, condemning the others to a more troubled career. As Taleb noticed, however, scalability is not only a propriety of technological development: even evolution is scalable, as only those who are more able to adapt survive. In the long run, only the best DNA will reproduce itself (Taleb 2010, p. 30). Another example of scalable dimensions is the water intake of a person: whether you drink a great quantity of water or nothing in a day, that quantity will influence minimally the yearly intake. In a context ruled by non-scalar dimensions, “when your sample is large, no single