There is a rich literature on culture-bound syndromes [0], but the same phenomenon is visible in certain criminal behaviors. To state it succinctly, crimes can

There is a rich literature on culture-bound syndromes [0], but the same phenomenon is visible in certain criminal behaviors. To state it succinctly, crimes can be memes. In the US, for instance, the school shooting is a meme: it's just what you do when you are massively angry at society and want to take revenge on it. Previously, "going postal" [1] was a meme amongst angry postal workers. In Italy, several years ago, there was a string of incidents of rocks being thrown from highway overpasses, striking cars. The government reacted by numbering all overpasses to make reporting easier, but AFAIK what really kept it from becoming a meme was an informal agreement with the media to relegate such news to small articles in the inner pages. When this was done, the number of imitators quickly petered out, and the meme disappeared. As for acid attacks, this is a meme that came from south-east Asia (e.g. Pakistan), where it was endemic a few decades ago. It spread to the UK due to its large population of immigrants from those countries, and for a while it was mostly confined within the Asian (in the UK sense) community, but it has now spread into the general population. This is clearly an unpleasant observation, but it is quite obvious if you have paid attention to the crime news over the last few decades. I remember acid attacks in the UK making the international news when I was a child. Back then they followed what the NPR article calls the "global pattern" ("males attacking young women and girls, relating to rejected sexual advances or marriage proposals or dowry-related attacks"), and the attackers were not native Britons. But if we could look at detailed statistics for this crime, I bet we would see both an increase in prevalence, and an increase in the percentage of British perpetrators. It is very tempting to ascribe these criminal memes to purely non-cultural factors, such as the availability of firearms in the US, and their limited availability in the UK, but it does not really work. School shootings were not always as prevalent in the US as they are now [2], nor is their prevalence proportional to that of guns across countries [3]; rocks and overpasses still exist in Italy [citation needed]; and the availability of acid in the UK has not increased relative to other cheap instruments of harm (e.g. knives, hammers), nor relative to other countries. BTW, the fact that acid attacks existed in Victorian times (but how common were they?) has no bearing on any of this. A meme can die out in a place and later be reintroduced from another source, just as a living organism can (e.g. horses in America). [0]: https://en.wikipedia.org/wiki/Culture-bound_syndrome https://en.wikipedia.org/wiki/Culture-bound_syndrome [1]: https://en.wikipedia.org/wiki/Going_postal https://en.wikipedia.org/wiki/Going_postal [2]: https://en.wikipedia.org/wiki/School_shooting#cite_note-nyr20151019-40 https://en.wikipedia.org/wiki/School_shooting#cite_note-nyr2... [3]: http://www.cbc.ca/news/world/small-arms-survey-countries-with-the-most-guns-1.3392204 http://www.cbc.ca/news/world/small-arms-survey-countries-wit...