I wonder if they properly controlled for the type of concert. In my experience, moshing will vary by genre with hardcore moshers tending to be more independent

I wonder if they properly controlled for the type of concert. In my experience, moshing will vary by genre with hardcore moshers tending to be more independent (see: windmills and kung-fu kicks). I also recently swapped coasts and noticed that West Coast pits seem to seek out the torodial "circle pit", while East Coast pits a more chaotic. It is a neat idea for a paper, but it seems like it needs a bit more thought to be useful for real-world applications.