Lincoln vs. Kennedy or a thing about coincidences

According to Wikipedia a coincidence is a remarkable concurrence of circumstances that have no apparent causal connection with one another. A famous example is a list of coincidences between Abraham Lincoln and John F. Kennedy. On the internet you can find loads of facts about those two presidents that seem weirdly similar. Did they really have some kind of a special connection?

^{)Abraham Lincoln's assassination; Wikimedia}

It is true that Lincoln was first elected to Congress in 1846 and Kennedy exactly a hundred years later, in 1946. Similarly the first of them became a president in 1860 and the second in 1960. Both had seven letters in their names and both were shot in the head on Friday and had a successor named Johnson.

However, after a short research it turns out that not every coincidence on the list is true. For example you can read that Lincoln's assassin was born in 1839 and Kennedy's in 1939, although the real date of birth of John Wilkes Booth was May 10th, 1838. Another allaged coincidence is that Lincoln had a secratary named Kennedy and Kennedy a secraetary named Lincoln. Even though the second part is true, there is no information about someone with a name Kennedy working for president Lincoln.

It is also worth noting that people looking for those coincidences focus only the similarities completelly ignoring the differences in the biographies of the two presidents. Even though many events in Kennedy's life took place exactly a hudred years after same events in Lincoln's life, there is no rule. For example Lincoln was born in 1809 while Kennedy in 1917, Lincoln died in 1865 while Kennedy in 1963 and so on. The name Lincoln does in fact have 7 letters as well as Kennedy and John Wilkes Booth and Lee Harvey Oswald both have 15 letters. But it's easy to spot that in the first case we are looking only at surnames and in the second case weare looking at full names. You can as well reverse it and say that Booth has a different number of letters than Oswald and John Fitzgerald Kennedy different than Abraham Lincoln who didn't even have a middle name.

^{John F. Kennedy before his assassination; Wikimedia}

After a closer look you can also see that some of those facts are not as significant as they seem. First of all, both having a seven letter name is not very unusual if you know that the average second name of an US president is 6,64 letters long. The fact that both died after being shot in the head also shouldn't be shocking - it's just a very common target for assassins.

So if there is no unexplained connection between those two, can you find different political figures with similar coincidences? It turns out you actually can. In 1992 Sceptical Inquirer magazine even organised a competition to find them. Two winners were picked. The first one found 16 coincidences between Kennedy and a former president of Mexico, Álvaro Obregón. The second created a list of 21 presidential pairs and similarities between them.

Coincidences may seem unbelievable but there nothing paranormal about them. According to the "law of truly large numbers" with a large enough sample, any odd thing is likely to happen. For example one person being hit multiple times by a lightning seems unlikely but if you take into consideration the number of people on Earth and the number of storms, the probability is not that small. Human brain is evolutionarily predisposed to look for patterns. It is undoubtedly useful but it also has some drawbacks - we sometimes feel like there is pattern when in fact there isn't. If you have enough motivation and enough time you can find connections between anything.

^{sources:
https://www.snopes.com/fact-check/linkin-kennedy
https://www.csicop.org/si/show/coincidences_remarkable_or_random
https://www.huffingtonpost.com/entry/lincoln-kennedy-coincidences_n_2829442?m=false
https://www.youtube.com/watch?v=sHCHEykUxP4
Pictures used under Creative Commons or Public Domain licence}