Communal vs. private rituals and taboos
Although our society has become so afflicted by obsessive-compulsive behavior, the central feature seems to not get so much attention -- namely, that it is a way for the person to isolate themselves socially. I don't mean only the far-out freaks, whose extreme deviation makes them off-putting. Even in milder forms, the main goal (whether conscious or not) seems to be social isolation.
Most rituals and taboos that you read about are group-level affairs: Muslims don't eat pork, pray five times a day facing Mecca, and so on. They separate in-group from out-group members, and tend to de-individuate the in-group members, for example by having them assemble and chant in unison. Thus they enhance social cohesion.
But with the OCD-like behaviors, they step things down to the individual level: I have a personal list of 500 things that I don't eat, along with a list of 500 nutrients I must eat every day, my iTunes playlist accepts post-retro-hardcore-tronica songs but rejects neo-post-retro-hardcore-tronica, etc. By having so many entries on the list of approved and unapproved thoughts, words, and acts, the chance is nil that my list will coincide with anyone else's.
So to me, everybody else becomes the out-group, a strategy that is especially welcome to avoidant types. Performing my own rituals and observing my own taboos strengthens my internal cohesion, where I may have been in doubt before; doing all the proper things according to my list gives me an ego boost.
The real clincher here is that in the DSM's criteria for Obsessive-Compulsive Personality Disorder, miserliness comes up. Why? That doesn't seem logically related to the other criteria, which are variations on "inflexibility". Why don't these OCD types make lists of who to donate time and money to, weighted by an inflexible system of who's more deserving than who else, and adhered to with perfectionism -- the checks always being mailed on the same date in the month, roaming the streets during a certain fixed schedule looking for panhandlers, always with the same amount of cash ready to donate, etc.? Why not strictly force yourself to put 75% of one month's income toward buying gifts for friends and family before Christmas?
But if the main function of OCD is to isolate oneself socially, in the same way that the in-group isolates itself from the out-group with rituals and taboos, then it's no surprise that such people are rigidly stingy rather than rigidly generous. It's no accident that the most famous hoarder in American culture is nicknamed "the Grouch".
By contrast, the de-individuating crowd rituals and taboos make the in-group members more altruistic toward each other -- leaving money in the donation plate, taking part in a canned food drive, book drive, winter clothing drive, and so on.
I used to think that during cocooning / falling-crime times, there was a decline in ritual. But perhaps it's more of a re-allocation of ritualistic and taboo-related behavior from the communal sphere to the private sphere. Yet another way in which a falling-crime period tends to make us a little crazier.