[ermintrude]

I read a book once - I think it was the Gift of Fear (but I might be wrong) - that said that plane crashes often occur in clusters, same with other tragedies like mass shootings at schools etc. The author suggested this was because people who might do those things - or in the case of pilots, pilots who might want to commit suicide and take the plane down with them - get prompted to act when they see other incidents have occurred. So according to that author, these events are not random.

Obviously a civilian plane being shot down would lie outside this theory (he suggested more plane crashes were due to pilot depression than mechanical fault/other factors).

[lotsofmangos]

If these events were completely random, then we would expect them to happen in clusters. Randomness is pretty clumpy.

[lilsunnybee]

Actual correlations can be pretty clumpy too. Definitely have to look at the overall distribution.

[sazpaz]

Robert Cialdini also brings the same theory in his book Influence. Not only that a tragedy prompts other to the same action, but he showed some studies where a type of tragedy prompted a seemingly irrelevant event.

For example, 2 days after a suicide appearing on the news, it is significantly (don't remember the exact numbers) more likely for there to be a plane crash. He attributes this to the fact that some pilots that have had suicidal thoughts are triggered by the suicidal news.

Another interesting study looked at how mortality rates of car accidents are higher after suicide-related news. This study found a surprising number of car deaths in which the driver was stepping on the gas pedal, instead of the break, which might be an indicator of suicide.

[vidarh]

The study regarding car crashes also looked into the correlation between whether or not car crashes only killed the driver or other people too, and found a clear correlation in additional deaths:

Murder-suicides leads to more "accidents" with head-on crashes etc., while "clean" suicides with nobody else involved tends to lead to an increase in "accidents" that don't risk other peoples life.

"Influence" is a fantastic book. Though it's downright chilling in how it tears apart the illusion of how much control we have of how we act.

[michaelmcmillan]

I don't think mass shootings can be considered to be random events, although they probably occur in clusters - I think that's due to the extensive media coverage.

"Why does a psychiatric expert on these phenomena personally advise mainstream media outlets about how to handle these situations - and they do exactly the opposite time and again?" [1]

[1] https://www.youtube.com/watch?v=Stc42j4Nz2w