We have outsourced the job of interpreting ourselves to the modern life sciences. The decoding of the human genome will tell us who we really are, pledged the gene-merchants. Brain scans will tell us who we really are, swore the neuro-hustlers. And what did we get? We got suckered. It turns out that humans have roughly as many protein-encoding genes as a fruit fly, and that fMRI scanning is still such an inexact art that a team of satirical neuroscientists have demonstrated significant "brain activity" in a dead salmon.

This fascinating, lucid and angry book by the sociologist Hilary Rose and the neurobiologist Steven Rose (they are married) boasts abundant targets and a lethally impressive hit ratio. They decry the entrepreneurialisation of science – "wealth creation is now unabashedly formalised as the chief objective of science and technology policy" – not least because it actually impedes science. ("PhD students can work for months on a project only to find that they cannot continue as they have run into a patent.") They lambast the "armchair" theorising of evolutionary psychology, with its ungrounded assumption that we have "stone-age minds in the 21st century". They scorn the "neuromyths" sold to the educational establishment, with the result that schoolchildren become the unwitting subjects of uncontrolled experiments in applying alleged lessons from animal psychology to the classroom.

The book performs in high style the necessary public service of recomplicating the simplistic hogwash hysterically blasted at us by both uncritical science reporters and celebrity scientists. (The authors are very funny about Richard Dawkins, who clearly doesn't understand what a metaphor is.) Here are the knotty histories of molecular biology and evolutionary theory, with explanations of why evo-devo and epigenetics make the old genetic determinism untenable, and why there is hardly ever "a gene for" something. ("Ninety-five genetic loci have been found related to blood lipid levels," the authors write, "possibly hundreds of genes might be implicated in coronary heart disease, and around a hundred in schizophrenia.") They show how and why both genomics and stem-cell therapy have thus far failed to usher in a miraculous new age of medicine, and observe sorrowfully that, even as the media storm of neurogibberish rages unabated, Big Pharma is shutting down research into mental health disorders in favour of more tractable (and so profitable) diseases.

Science is also political, the Roses insist throughout. We are living through the "commodification of bioinformation", as vast new DNA "biobanks" are built from national populations. The authors celebrate the resistance of Icelandic citizens to the rapacious exploitation of one such biobank by an American corporation, but David Cameron is already planning for NHS records to be made available to private companies. Citizens could be persuaded to participate in large-scale biomedical projects, the Roses argue, by appealing to the value of solidarity – were it not for the fact that the contrast now visible to everyone between welfare policy for bankers and welfare policy for the poor shows exactly what our masters think of solidarity.

"Who benefits?" the authors ask doggedly and repeatedly of modern technoscience. And the answer is usually: not us. With sardonic perspicacity, they note that the possibility now on the horizon of screening for genetic predisposition to diseases "serves to expand the potential demand for drugs to people with no symptoms". Such screening, they write, constructs "a new kind of patient, the at-risk individual". And so, "personalised genomics creates a fresh market of unforeseeable size carrying with it an unpredictable but potentially vastly increased drug bill to be met by the NHS."

The authors also rehearse the history of 20th-century eugenics, from the Nuremberg doctors' trial and onwards with nary a blip: many Nazi scientists carried on working after the war, while America began cheerfully experimenting on its own citizens with psychotropic drugs and radioactive materials. The authors segue from such black tales into the "new science fiction" of "designer babies" and pills or genetic hacks for self-enhancement: to make the already healthy even healthier, or cleverer, or longer-lived. The Roses don't really engage, however, with the reasoning offered by some philosophers in favour of such enhancement. They invoke the dread name of Galton and cry "consumerist eugenics", but that is merely an attempt at showing guilt by association; it's not an argument.

Just occasionally, too, the authors' entertaining belligerence leads them to employ weapons they deny to their enemies. They are sceptical of neuroscanning experiments, they explain, because "the unit of analysis is individual, yet humans are social animals with brains that have evolved to enable their owners to survive in complex social environments, not to solve abstract problems". Well, hang on: this claim that we have not evolved to solve abstract problems sounds awfully like the kind of just-so waffle from evolutionary psychology that they elsewhere lampoon. Plainly we can solve abstract problems. Where is the evidence that this capacity is not evolved? And why, moreover, should we even accept at face value the Roses' hard-and-fast separation of abstraction and sociality, on which depends their implicit hypothesis that you can evolve one or the other but not both?

Discussing meanwhile the sexism of many male scientists and the horrific brutality formerly routine in animal experiments, the authors ask: "At the level of the masculine unconscious do men still understand themselves as licensed to be wantonly cruel to women and laboratory animals alike?" But what is this "masculine unconscious" of which they speak? Is it present and identical in all men? And if it really exists, where has it been shown that it once did understand things this way? Had an evolutionary psychologist or a hawker of gendered brain essentialism written that sentence, the Roses would rightly have torn it to shreds. Perhaps, though, it should be accounted another triumph of their superbly engaging book that it primes the reader so well to be alert to such problems of scientific rhetoric, even within its own pages.