I'll Have What She's Having: Mapping Social Behavior

Big subject, slim volume. The authors, two anthropologists and a marketing consultant, aim to outline models for copying behaviours and consider why people latch on to ideas. Well, not even "why", exactly. They identify pathways for transmission: how it comes about that people pick certain behaviours instead of others and start to change the landscape of social norms. They are fairly modest about how powerful, precise or predictive such mathematical models can be.

While there are interesting ideas here in a random scatter of cases and anecdotes, the trouble is that it makes the reader feel equally random: scatterbrained, as if you've been doing idle searches on Google or browsing Wikipedia all day. The kind of theoretical coherence found in the elegant, simple propositions of Richard Dawkins' The Selfish Gene or Amotz and Avishag Zahavi's The Handicap Principle: A Missing Piece of Darwin's Puzzle - books that made you feel like a genius, armed with a new perspective on the world - is not evident.

This reflects the times we live in; trains of thought are not in fashion. I'll Have What She's Having is predicated on viral internet/Facebook/Twitter modes of human decision-making. Click the "like" button; a sign-up for Twitter follows; order skinny lattes to go. The book mostly deals with low-cost decisions on tree-like algorithms that matter little to the decision-maker (unless, of course, you organise a "riot" on Facebook and only the police turn up). But for pop-up advertising CEOs or Facebook app inventors, flipping your decision one way or another matters. And this book is written with them in mind.

Anyone engaged with the "social brain" hypothesis will agree with the authors that we cannot explain human cultures of decision-making without a "we" perspective. But owing to the constraints of the computer social-network models they adopt, I am unconvinced that they get at processes for the creation of "we". What about the ways people express collective intentionality, be it on the football terraces, in church or in taking to tents on Tahrir Square? Horizontal coalitions such as Occupy Wall Street or the Climate Camps show people acting together even when they are highly resistant to quick-and-dirty copying strategies, and jealously guard their autonomy.

Countering the Pleistocene-fossilised-brain notion touted by evolutionary psychologists, Alex Bentley and his colleagues argue strongly that today we take cues from the environment we live in, which is something that evolutionary ecologists would support. While there may be a case for emergent phenomena of self-organisation at different scales and densities of population, it needs more careful argument. If we go on the Hajj or take the Tube in London's rush hour, we are plunged into mass movements of people, but we retain our cognitive ceiling constraints of neocortex size, which means that we only comfortably handle social engagement in networks of some 150 individuals. But there are mechanisms in the lives of hunter- gatherers as well as football supporters and members of autonomous movements - experiences of ritual intensity, classificatory kinship systems, formats for people's assemblies - that enable people to engage socially, meaningfully, with vaster numbers. I will get much more interested when copying and social-diffusion models begin to address these.

The point where I really wanted to throw this book across the room came unfortunately early, on page 30. Within two sentences, the authors elide mirror neurons with the concept of intersubjectivity. Mirror neurons are found in creatures with grasping hands; they fire in the brain of one individual who sees another reach for a piece of fruit, as if rehearsing the movement. Mirror neurons may provide a basic substrate for the imitation of actions, but they do not grant intersubjectivity or anywhere near it. Willingness to share what I am thinking with you and to seek to know what you are thinking of my thoughts is a unique human trait based in shared intentionality. Monkey and ape politics preclude the cooperation required for such two-way mind-reading.

Reducing intersubjectivity to being "wired to copy" is a travesty. Human copying, with our deep social minds, is not merely selfish behaviour, but occurs in a framework of cooperation upheld by collective intentionality. The authors start their second chapter by suggesting that play may be a lens for understanding much of human behaviour. Childplay is indeed the scaffold for shared and collective intentionality, hence understanding norms and rules. Disappointingly, however, the authors here invoke standard economic game theory, rather than exploring human creative tendencies to mimic, joke and laugh at one another's expense - truly reflecting empathy and perspective reversal.

A case study of Samsø, a Danish island that became an exemplar of collaborative local green energy projects, deserved its own chapter. I suspect the mechanisms that led to people adopting and owning community eco-energy schemes are best understood through good, old-fashioned ethnographic fieldwork. The authors ask: "How can we turn the world into a giant Samsø?" to deal with species-threatening climate change. But this book's viral models leave out too many powerful factors of human experience - among them ritual, congregation and play - to be able to provide completely illuminating answers.