Cognitive Surplus, By Clay Shirky

Comparing the rise of the web to the invention of Gutenberg's printing press has become a familiar cliché, and there are few theorists of the internet age still able to wring any new significance from the association. Clay Shirky, however, is one of them. The printing press was expected to prop up the religious culture of the 15th century by making its central texts more widespread. Instead, it encouraged intellectual variety.

The modest ambitions of the early internet were to impart information from the top down, like books or television. Instead, it enabled mass interaction and creation. "What seemed a new channel for traditional media is actually changing it," Shirky writes in Cognitive Surplus: "what seemed to threaten cultural uniformity is actually creating diversity."

Compared to his previous volume, Here Comes Everybody, this book's title is hardly a catchy one. But the concept is straightforward enough. In the post-industrial age, people enjoy leisure time unavailable to their ancestors, and until recently that time was largely given over to a passive, purely consumptive activity: watching television. The internet has turned many of those passive hours into productive ones. Aggregate the free time of every person with a broadband connection, and suddenly society finds itself with a vast creative resource: a "cognitive surplus". Social media, Shirky's field of study, allows that resource to be pooled and put to use.

Thus "the people formerly known as the audience" have used their cognitive surplus to create the low-cultural Lolcats (a website that collects amusing photographs of cats with silly captions), the loftily-conceived Ushahidi (which began as a service for users to track ethnic violence in Kenya, and has become a versatile tool for NGOs the world over) and the likes of PatientsLikeMe (a platform for patients to share their experiences of illness). In Shirky's view, these social creations fall into a series of categories: personal, communal, public and civic – the last describing those shared projects whose mission is nothing less than to transform society. These high-minded web ventures, he suggests, are the most valuable of all.

Shirky is an original thinker, a compelling stylist, and a sage with a remarkable record of accuracy. Here Comes Everybody will likely become an enduring (electronic) document of social media's early spread. Cognitive Surplus is a manifesto for what's next – or what ought to be.

Using behavioural research, the optimistic author insists people are far less driven by money and self-interest than we've allowed ourselves to believe. "Many of the unexpected uses of communications tools are surprising," he writes, "because our old beliefs about human nature were so lousy." Such triumphal collective endeavours as Wikipedia, the online encyclopedia, are the work not of paid employees but amateur enthusiasts.

He also gives the lie to the idea that new technologies have altered human behaviour, arguing convincingly that they have allowed merely for more elegant incarnations of old habits. Teenagers have always been emotional oversharers, be it by telephone, text or Facebook. People have always shared music, by hand or via Napster. Grandparents have always cherished communication with their families, only now letter-writing has morphed into emailing for an unexpected generation of tech-savvy "silver surfers".

If there's a bogeyman in Cognitive Surplus, it's that old time-waster, television. But the web has changed TV, too. Take Lost, as Shirky does – a show as much new media as old. Its viewers weren't just viewers," he argues, "they collaboratively created a compendium of material related to that show called (what else?) Lostpedia."

Cognitive Surplus ignores the more sinister uses of social media. If the web can be used to monitor instances of violence, then it can be used to organise them. And while it may present an endless diversity of choice, large companies can also use it to monopolise consumer preference. The internet facilitates the darker side of human nature just as it does our best instincts.

Shirky knows that; it simply isn't the point of this book, which looks forward to a Utopian future, or at least a Wiki-topian one, where large groups of people will continue to come together instantly in their free time to solve problems, change society for the better and, yes, share funny pictures of cats.