White Teeth by Zadie Smith (Penguin, £6.99, pp542)

It seems you can't step onto a train at the moment without somewhere spotting the lurid red, green and turquoise cover of Zadie Smith's White Teeth. Were it not for the current fad of (physically) grown adults reading children's literature in public, these colours would in all likelihood have reached the same level of transport ubiquity as did the blue and beige of Captain Corelli's Mandolin a few years ago. White Teeth has certainly had the hype: it has won the Whitbread First Novel Award and the Guardian First Book Award, Salman Rushdie has extolled it (possibly ecstatic at his apotheosis from literary author to literary character: one of Smith's creations is punished for attending the burning of the Satanic Verses in Bradford), and the author's name has become synonymous in the broadsheets with all that is young, hip and literary. Much has been made of the book's multiculturalism, but less attention has been given to its literary merits -- does it really deserve all this lavish praise?

The publishers are understandably desperate for you to think so: the story of Smith's signing has already passed into publishing legend. She had barely written eighty pages when the bidding war began. Only 21 at the time, Cambridge educated, photogenic and of mixed ethnic origin -- in short, a publisher's PR dream -- Smith landed a rumoured £250,000 two-book deal without such trivial nuisances as needing to have actually written a book. It is certainly possible to see in the first chapters what attracted the publishers: the writing is fresh and lively ("the position of the planets, the music of the spheres, the flap of a tiger-moth's diaphanous wings in Central Africa, and a whole bunch of other stuff that Makes Shit Happen had decided it was second-chance time for Archie"); the characters are colourful in all senses of the word (Samad and Alsana's arguments tend to terminate in fist fights on the lawn); the dialogue is believable and punchy; and the narration is witty and -- to use a term frequently bandied about in association with Smith -- sassy (she has bashfully described her own style of writing as being "like a script editor for The Simpsons who'd briefly joined a religious cult and then discovered Foucault"). It is also true that she has at the very least attempted a first novel that does not conform to the stereotype of thinly-disguised introspective autobiography (though too much has been made of this, most reviewers having apparently overlooked the fact that one of the central characters, Irie, bears an uncanny resemblance to the author -- though Smith has modestly given Irie buck-teeth; besides which, one of the best debut novels of recent years, Saving Agnes by the often underrated Rachel Cusk -- which also won the Whitbread -- does indeed conform to this stereotype). It is easy to understand how the publishers must have believed all this was going somewhere. Unfortunately, it wasn't.

White Teeth (somewhat awkwardly) follows three generations of two families who have come to London from Jamaica and Bangladesh, connected by the central friendship of Archibald Jones and Samad Iqbal, an unlikely pair who met during the last months of World War II. The frequent leaps in time and place add much colour to the proceedings and give the impression of an expansive plot; it is only when the reader steps back and looks at the whole that the relevance of all this (admittedly entertaining) background becomes somewhat oblique. Despite the introduction of the theme of genetics rather late in the story, there is never any convincing connections made, and if the idea was to show how family history and genealogy determine the personalities of the younger generation of characters, its execution is half-hearted and what is apparently intended as a major theme never seems more than an afterthought. Even the whole Mangal Pande subplot never properly resolves itself; Millat's actions at the end are a rather weak attempt at a cross-generational link, and neither properly echo the story of Pande nor have any significant repercussions.

This, in fact, is one of the novel's central failures: the themes of relations between generations and living up to family expectations are key to the coherence of the whole, and yet are never satisfactorily explored. For despite the frequent (and tenuous) invocations of teeth, the metaphor of the title adumbrates the supposed importance of these themes in a scene in which the three children, Magid, Millat and Irie, visit J. P. Hamilton, an old man to whom they are to give food for the Harvest Festival (a school tradition Samad, father of Magid and Millat, has opposed on religious grounds). Roots are what are important, we are told; lies rot the roots, and wisdom teeth -- "they're your father's teeth, you see...," says Hamilton to the children: "So you must be big enough for them." He goes on to advise them to have their wisdom teeth removed as early as possible. And this is the crisis the children must face as they grow up: are they big enough to accommodate their own roots and the uncomfortable truths in which they are implanted, or should they reject them and cut off the past? The metaphor is sound and proffers much potential, but unfortunately, like so much in this novel, it is wasted and never allowed to attain any real poignancy.

There are points at which Smith's language is wince-evincing: she is prone to mixed metaphor ("if we are to go beyond the heart of the matter to its marrow, beyond the marrow to the root" -- ouch); on occasions she even plain misuses words ("there's Babycham and some other inexorable shit over there" -- who would speak such nonsense?); there are anachronisms that will stand out to anyone of the same generation (the use of the word "blatantly" in every sentence was a youth fad of the early nineties, not the mid-eighties); and she frequently descends into the twee (the children's shouts of "I tax that!" at items they like; a child overhearing talk of marijuana and asking "What's mary wana?").

Such minor gripes would of course be unimportant if the novel worked as a whole, but for all the wonderful characters, stories and ideas it finally fails to deliver on anything more than a superficial level. One of the major flaws of this book is the number of its inhabitants. Smith has an undeniable gift for creating engaging oddballs, but, like someone who has recently taken up pottery and inundates friends with unwanted and malformed ashtrays, she does not know when to stop -- even after the halfway mark major characters are still being introduced -- and seems unable to decide who the central characters really are. Ultimately she creates and gives attention to so many characters that most of them end up with nothing much to do, and she does not have the space to characterise them properly or develop their personalities in any real depth -- even in 540 pages: "Niece-of-Shame" Neena and her girlfriend show much promise, but make precious few appearances and have no narrative impact at all; Ryan Topps has little to do beyond his unconvincing transformation from scooter-fanatic to Jehovah's Witness; Joshua Chalfen makes the transition from minor to major character in the last few chapters, only to have absolutely no purpose save that of introducing a patronisingly (and offensively) stereotyped animal rights group who, again, do nothing and have absolutely no impact on the lives of any of the major characters; conversely, Magid, who starts life as a major character, is sent away only to return much later as a minor character who does little except mildly disappoint his father (though with no important consequences) and become an assistant to Marcus Chalfen.

Which brings us to the other major flaw of the novel: to continue Smith's teeth metaphor, the rot really sets in when the Chalfens enter the book, approximately halfway through. They immediately dominate the novel despite their tired and lazy characterisation: the Chalfens are dated clichés straight out of the BBC school of Middle Class Intellectual Families With Parents Raised In the Sixties, though Smith apparently believes they are wonderfully witty creations. (If you want a cheap laugh at such easy targets as bleeding-heart liberals, David Wilson's great Love and Nausea does it much better). The flaky Joyce Chalfen, in particular, with her tawdry comparisons of human growth to that of flowers, is grating beyond belief: we have seen her before in a hundred sitcoms from both here and the US. The whole family remains two-dimensional, and the purpose of their introduction into the narrative is unclear: they are apparently intended as a catalyst in the breakdown of the two central families, the Bowdens/Joneses and the Iqbals, but this breakdown never results in anything more than a small argument on a bus (in which the main characters get slightly irritable with one another and then get over it).

White Teeth is usually described as a comic novel, but the only aspect that really justifies this description is the staple comic novel denouement in which all the characters are drawn to the same place at the same time for different reasons. Such endings are necessarily contrived, but Smith's seems especially forced and entirely misses the point. The classic comic denouement (that such authors as David Lodge and James Finley Boylan write so beautifully and believably) brings together disparate characters with contrary motives, resulting in choreographed chaos and a closure that seems in retrospect to have been the inevitable result of everything that has gone before. Not so here. The ending is unconvincing and poorly crafted: Smith's characters are all drawn together to the unlikely event of a science exhibition, and almost all of them end up as spectators rather than actors. It is as though Smith felt compelled to bring them all together in order to end the book definitively, but then had no idea what to do with them when she had them all before her. Because nothing actually happens. And there are no repercussions. There is a moment when it seems that one of the major characters has inadvertently killed another one. But then we are told in a brief, summarised, wrap-it-up ending that the victim survives and the perpetrator gets away with it, and they all carry on pretty much as before. The identity of another character is revealed as though it is intended as a twist that throws into doubt the central friendship between Samad and Archie, but it is unlikely that there is a single reader who didn't guess the truth right at the beginning of the book, and anyway, the pair accept the truth without any ill-feeling.

Which is more than can be said of the reader, who is ultimately left feeling curiously empty. The characters are likeable enough, but you never really empathise with them, there is no emotional involvement. And you are left with the suspicion that no one has been changed in any way and that nothing has actually happened. The sensation is discomfiting: it is as though the book has a pulse but -- bizarrely -- no heart. There is something in all this of the Emperor's new clothes, of course: everybody is raving about it (It's a celebration of multicultural Britain! This is a Good Thing!) -- but ultimately, there is nothing actually there. The genetic modifications of a mouse, patents, family history that spans a century, anecdotes from Jamaica and Bangladesh, an animal rights group, a militant Muslim group with the unfortunate acronym KEVIN, the exploits of two men at the end of World War II, gardening -- such diverse strands make for great blurb on the back of a book, but if they are not drawn together into an organic whole, if they are not all used as tools to tease out greater themes -- and here they are not -- then they fail to coalesce into a complete novel and remain experiments in and exhibitions of erudition on the part of the author. And Smith likes to wear her erudition on her sleeve (in a recent Guardian article in which writers were asked to recommend some holiday reading, Smith pointed the reader towards such little-known gems as Shakespeare, Tolstoy, George Eliot, Milton, Kafka and Nabakov).

It is tempting to compare the publishing and reviewing frenzy for this book to the Chalfens' enthusiasm for Millat -- the desperation for something different without looking too far beyond the surface. But this would be grossly unfair to Smith herself, who undeniably has talent and may yet one day write a great novel. It's just that this isn't it. Smith recently said that she will write only one more book (The Autograph Man -- she is contractually obliged to do so), stating that she "doesn't have a duty to write." She then intends to enrol on an MA course at Harvard next September, having told the Daily Express: "I want to study some more, then become a professor." (This sort of sweeping overconfidence permeates White Teeth.)

Not a Great Novel, then, but undoubtedly a decent debut, severely let down by the second half, the lack of any real character development, a confusion of themes that are only superficially explored, an overly contrived ending and a story in which nothing really happens and nothing important is ever at stake -- most of which could more easily be forgiven in a less-hyped debut. But ask any dentist: the whitest teeth are not necessarily the healthiest. It is difficult to shake the feeling that had Smith been allowed a few more years to work on the book in anonymity the result might have been something as special as the hype would have you believe. We can only hope that Smith finds the time to write a few more novels in the brief period she expects to spend attaining her professorship.