I spent Thanksgiving weekend at my mother’s house in the small town of Selinsgrove, Pa. On Friday the local paper’s unsigned editorial urged shoppers to remember their sense of decorum — no shoving, grabbing or cursing, please.

I smiled an indulgent big-city smile over the fact that the newspaper would devote an entire editorial to this. But I haven’t been laughing since I heard a man was trampled to death by a crowd of Black Friday shoppers.

Richard Beck did a sharp analysis of the situation using principles of social psychology. But still, he’s left feeling that doesn’t quite explain enough. Certainly, this is the sort of thing that reminds us of the near proximity of evil. I recall another article on the topic quoting an employee who realized that any of the customers he was talking to could have been one of the ones who stomped over his colleague.

As I said to Richard, I don’t really understand why someone would camp out all night — after a dinner party! in November! — to get a cheap computer. But this did make me think about how common, in my lifetime, is the experience of waiting in a long line for something to open. This seemed to get rolling with the Star Wars movies, which created such a venerable tradition of line-waiting that some fans revived it for the prequels, even though in the days of Internet ticket ordering it is not really necessary. And actually, queuing up for things like that can even be fun. I remember waiting outside of San Francisco’s mammoth Coronet theater on the opening night of Independence Day in 1996, chatting with friends, eating takeout pizza. When we got inside, the crowd lustily cheered and booed the action, and a good time was had by all, in spite of the fact that the movie was really pretty dumb. Treating a movie like it was good almost made it good by sheer force of will.

Unfortunately, marketers seem to have taken to heart the lesson that, basically, if you can build up that much excitement over Independence Day, you can build it up over anything. Marketers know their social psychology — in fact, many social psychologists go into marketing, as my professor on that subject ruefully pointed out. That’s why I think the company deserves some of the blame here; the creation of Black Friday, with its “doorbuster” sales, deliberately uses the phenomenon of mob frenzy.

But it’s also true that in many cases this psychology is benevolent. It was harmless enough in Independence Day, and Star Wars; indeed, my experience with sci-fi movies and conventions is that their crowds are exceptionally well-behaved, drawn together by their shared enthusiasm. Maybe Black Friday can be fun that way too. But what was different about the Wal-Mart in Long Island?

Actually, the first thing that may be different is the very fact that it’s a Wal-Mart. Wal-Mart is one of the few retailers to be doing well these days, thanks to what the industry argot calls “trading down.” That is, when people are short of funds due to a recession, some will, say, buy a television at Wal-Mart who used to buy televisions at Best Buy or Circuit City (which, not coincidentally, recently went bankrupt). Materially speaking, trade-down shoppers aren’t that badly off; after all, a cheaper TV is still a new TV. But one well-known aspect of human psychology is that people feel more keenly the absence of things they once had, than that they never had. And so the mental state of the trade-down shopper will likely be at least a little bitter. Add to that the fact that today’s trade-down shopper is more likely than others to have recently been through a humiliating experience, like losing a job, defaulting on a mortgage, or being denied credit.

Don’t get me wrong: I’m not saying this is an excuse. These people were fighting for flat-screen TVs, not bread and water. But what I mean is, I can imagine this crowd’s mentality becoming the reverse of your typical sci-fi convention crowd. Rather than coming together out of their common love, they are brought together by their common lack, even shame. Although sometimes this can occasion solidarity, more often than not this can turn to mutual contempt. And then you plug in the factors that Richard describes, the vast numbers forming, the realization of scarcity … and so it goes.

By the way, am I the only one who remembers that there was a scene that was alarmingly similar to this incident in the movie Jingle All the Way? I never saw the film, but I remember it from the trailer. The thing was, it was played for laughs. I wonder if that could have been another factor in people’s neglect of the fallen man — it just seemed too absurd to be true.