The first day after London started burning, I spoke to Claire Fox, radical leftwinger and resident of Wood Green. On Sunday morning, apparently, people had been not just looting H&M, but trying things on first. By Monday night, Debenhams in Clapham Junction was empty, and in a cheeky touch, the streets were thronging with people carrying Debenhams bags. Four hours before, I had still thought this was just a north London thing. Fox said the riots seemed nihilistic, they didn't seem to be politically motivated, nor did they have any sense of community or social solidarity. This was inarguable. As one brave woman in Hackney put it: "We're not all gathering together for a cause, we're running down Foot Locker."

I think it's just about possible that you could see your actions refashioned into a noble cause if you were stealing the staples: bread, milk. But it can't be done while you're nicking trainers, let alone laptops. In Clapham Junction, the only shop left untouched was Waterstone's, and the looters of Boots had, unaccountably, stolen a load of Imodium. So this kept Twitter alive all night with tweets about how uneducated these people must be and the condition of their digestive systems. While that palled after a bit, it remains the case that these are shopping riots, characterised by their consumer choices: that's the bit we've never seen before. A violent act by the authorities, triggering a howl of protest – that bit is as old as time. But crowds moving from shopping centre to shopping centre? Actively trying to avoid a confrontation with police, trying to get in and out of JD Sports before the "feds" arrive? That bit is new.

By 5pm on Monday, as I was listening to the brave manager of the Lewisham McDonald's describing, incredulously, how he had just seen the windows stoved in, and he didn't think they'd be able to open the next day, I wasn't convinced by nihilism as a reading: how can you cease to believe in law and order, a moral universe, co-operation, the purpose of existence, and yet still believe in sportswear? How can you despise culture but still want the flatscreen TV from the bookies? Alex Hiller, a marketing and consumer expert at Nottingham Business School, points out that there is no conflict between anomie and consumption: "If you look at Baudrillard and other people writing in sociology about consumption, it's a falsification of social life. Adverts promote a fantasy land. Consumerism relies upon people feeling disconnected from the world."

Leaving Baudrillard aside, just because there is no political agenda on the part of the rioters doesn't mean the answer isn't rooted in politics. Theresa May – indeed most politicians, not just Conservatives – are keen to stress that this is "pure criminality", untainted by higher purpose; the phrase is a gesture of reassurance rather than information, because we all know it's illegal to smash shop windows and steal things. "We're not going to be diverted by sophistry," is the tacit message. "As soon as things have calmed down, these criminals are going to prison, where criminals belong."

Those of us who don't have responsibility for public order can be more interrogative about what's going on: an authoritarian reading is that this is a generation with a false sense of entitlement, created by the victim culture fostered, and overall leniency displayed, by the criminal justice system. It's just a glorified mugging, in other words, conducted by people who ask not what they can do for themselves, but what other people should have done for them, and who may have mugged before, on a smaller scale, and found it to be without consequence.

At the other end of the authoritarian-liberal spectrum, you have Camila Batmanghelidjh's idea, movingly expressed in the Independent, that this is a natural human response to the brutality of poverty: "Walk on the estate stairwells with your baby in a buggy manoeuvring past the condoms, the needles, into the lift where the best outcome is that you will survive the urine stench and the worst is that you will be raped . . . It's not one occasional attack on dignity, it's a repeated humiliation, being continuously dispossessed in a society rich with possession. Young, intelligent citizens of the ghetto seek an explanation for why they are at the receiving end of bleak Britain, condemned to a darkness where their humanity is not even valued enough to be helped."

Between these poles is a more pragmatic reading: this is what happens when people don't have anything, when they have their noses constantly rubbed in stuff they can't afford, and they have no reason ever to believe that they will be able to afford it. Hiller takes up this idea: "Consumer society relies on your ability to participate in it. So what we recognise as a consumer now was born out of shorter hours, higher wages and the availability of credit. If you're dealing with a lot of people who don't have the last two, that contract doesn't work. They seem to be targeting the stores selling goods they would normally consume. So perhaps they're rebelling against the system that denies its bounty to them because they can't afford it."

The type of goods being looted seems peculiarly relevant: if they were going for bare necessities, I think one might incline towards sympathy. I could be wrong, but I don't get the impression that we're looking at people who are hungry. If they were going for more outlandish luxury, hitting Tiffany's and Gucci, they might seem more political, and thereby more respectable. Their achilles heel was in going for things they demonstrably want.

Forensic psychologist Kay Nooney deals impatiently with the idea of cuts, specifically tuition fees, as an engine of lawlessness. "These people aren't interested in tuition fees. In constituency, it's most similar to a prison riot: what will happen is that, usually in the segregation unit, nobody will ever know exactly, but a rumour will emanate that someone has been hurt in some way. There will be some form of moral outrage that takes its expression in self-interested revenge. There is no higher purpose, you just have a high volume of people with a history of impulsive behaviour, having a giant adventure."

Of course, the difference is that, in a prison, liberty has already been lost. So something pretty serious must have happened in order for young people on the streets to be behaving as though they have already been incarcerated. As another criminologist, Professor John Pitts, has said: "Many of the people involved are likely to have been from low-income, high-unemployment estates, and many, if not most, do not have much of a legitimate future. There is a social question to be asked about young people with nothing to lose."

There seems to be another aspect to the impunity – that the people rioting aren't taking seriously the idea it could rebound on them. All the most dramatic shots are of young men in balaclavas or with scarves tied round their faces, because it is such a striking, threatening image. But actually, watching snatches of phone footage and even professional news footage, it was much more alarming how many people made no attempt at all to cover their faces. This could go back to the idea that, with the closure of a number of juvenile facilities and the rhetoric about bringing down prison populations, people just don't believe they'll go to prison any more, at least not for something as petty as a pair of trainers. I feel for them; that may be true on a small scale, but when judges feel public confidence seriously to be at issue, they have it in themselves to be very harsh indeed (I'm thinking of Charlie Gilmour). But there is also a tang of surreality around it all, with the rioters calling the police "feds", as though they think they are in The Wire, and sending each other melodramatic texts saying: "So if you see a brother . . . SALUTE! If you see a fed . . . SHOOT!"

Late on Monday night, news went round Twitter that Turkish shopkeepers on Stoke Newington Road in Dalston were fighting off the marauders with baseball bats, and someone tweeted: "Bloody immigrants. Coming over here, defending our boroughs & communities." And it struck me that it hadn't occurred to me to walk on to my high street and see what was going on, let alone defend anything. I was watching events on a live feed, switching between Sky and the BBC, thinking how interesting it was, even though it was audible from my front door and at one point, when I couldn't tell whether the helicopter noise was coming from the telly or from real life, it was because it was both.

The Dalston clashes remind us, also, that it wasn't just JD Sports, even though the reputation of that chain is, for some reason, the most bound up with everything that's happened. Smaller, independent corner shops, the kind without a head office in Welwyn Garden City, that aren't insured up to the teeth, were ransacked as well, for their big-ticket items of booze and fags. When a chain is attacked, the protection of its corporate aspect means that, while we can appreciate the breakdown of law and order, we do not respond emotionally. When a corner shop is destroyed, however, the lawlessness has a victim, and we feel disgusted. That's what drags these events into focus: not the stuff that was stolen, but the people behind the stuff.

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