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Why Everyone (else) is a Hypocrite by Robert Kurtzban is a manifesto for a good idea in neuropsychology taken to an absurd extreme, says Owen Flanagan

The idea that the mind might be more like a termite colony, an army of specialists with small jobs, than the singular res cogitans invoked by Descartes or the empiricists鈥� blank slate is now commonplace. In his classic 1997 book How the Mind Works, Steven Pinker channelled a widespread consensus when he wrote, 鈥淭he mind is not a single organ but a system of organs鈥� or mental modules.鈥�

Today, however, the concept of modules is now so aligned with the so-called strong programme of evolutionary psychology that it can be a call to arms, with accusations of 鈥渦ltra-Darwinian fundamentalism鈥� bandied against those who love modularity, and 鈥淒arwinian denial鈥� and 鈥渃rass behaviourism鈥� against those who eschew it.

This is unfortunate, since it obscures the fact that everyone believes in specialised mental faculties. When I toss you a yellow ball and you catch it, one area in your occipital lobes computes the colour and another the shape, while sensorimotor areas send messages to move your hand.

These visual, sensory and motor processors form a known system of connected modules. What remains unknown is whether the mind is modular at every level of cognition; how plastic the modules are; whether modules do more explanatory work than such traditional posits as beliefs, desires, individual histories and social ecologies; and how a unified self emerges from the mind鈥檚 modular architecture.

聯It remains unknown how a unified sense of self emerges from the mind鈥檚 modular architecture聰

Robert Kurtzban鈥檚 book is an advertisement for mad-dog modularity. Despite consensus that the mind is modular at some levels, many neuroscientists believe that the prefrontal cortices do a lot of generalised processing, which in the olden days would have been called 鈥渢hinking鈥�. Not Kurtzban. For him, the mind is a colony of competing, self-interested modules and nothing more. This, he claims, explains why we are such inconsistent creatures.

When Kurtzban wakes up, he both wants to stay in bed and wants to go for a run. What is going on? Duelling modules, he says. In another example, Fred is told he has terminal cancer but still makes plans for a cruise. Again, modules are the explanation. Sometimes modules cooperate, but other times they result in self-deception of the 鈥淚 can have just one or two drinks鈥� variety. In this case, short-sighted and long-sighted modules are battling it out.

Are these modules innate? Kurtzban never says. If they are, I guess they somehow evolved to compute 鈥済oing on a cruise鈥� thoughts or 鈥済etting news about terminal cancer鈥�.

Kurtzban鈥檚 ultimate aim is to explain moral hypocrisy 鈥� why we don鈥檛 apply the moral standards with which we judge others to ourselves. His answer? It鈥檚 your modules, stupid! When a man thinks 鈥測ou are sleazy for cheating on your wife鈥� but feels justified in cheating on his own, his modules, according to Kurtzban, are at war. Psychologists have a different explanation for such hypocrisy: I can rationalise my behaviour because I am in touch with my life and not yours 鈥� perhaps I know that my wife doesn鈥檛 love me any more 鈥� ergo the asymmetry. No modules need apply.

Modularity is a fruitful idea, but you wouldn鈥檛 know it from this slapdash book, which unfortunately is just a noisy manifesto for a good idea taken to an absurd extreme. In place of evidence and argument it offers chit-chat and jokes. If the mind was truly modular all the way up and down, with no higher-level thinking to self-censor, then most books would be like this one: a dump of what all the modules want to say. Luckily the best popular science writing suggests otherwise.