If you can get past the studied jauntiness and occasionally histrionic style, Daniel Bergner's What Do Women Want? says some useful things about female sexuality. As with other recent books on the subject – notably Naomi Wolf's polemic, Vagina – it knits together anecdote, case study and scientific discovery to overturn some tenacious assumptions: that, unlike men, women aren't hardwired for promiscuity; that security and emotional connection are the most important factors in women's sexual transactions; that, above all, sexuality in women is constitutionally milder than in men, rather than the result of centuries-old social conditioning. Or, as Bergner puts it: "That women's desire – its inherent range and innate power – is an underestimated and constrained force, even in our times, when all can seem so sexually inundated, so far beyond restriction."

This line of argument was perhaps shockingly countercultural in the 1990s. Now it almost feels overstated; it's great to liberate women's sexuality from historical restraints, but read in the wrong mood, or after watching too many episodes of Girls, it sounds like yet another obligation. Along with everything else on your to-do list, you are required to show off your inherent range and innate power like a lab rat on a dopamine surge.

Rats are a big part of this book, as they often are in pop-science, which could boil down many of its arguments to "because a rat did it". Bergner spends time, as Wolf did, watching scientists watching rats for signs of what in humans might be considered inverse or atypical gender behaviour. The same goes for human experiments, in which women are hooked up to electrodes and shown porn. Sure enough, the female rats are more sexually aggressive than the males, and the porn-watching women as indiscriminately aroused as the men in the trials, right down to being turned on by copulating bonobos – no candles or box of Milk Tray required.

The complicating factor, of course, is that arousal does not always equal desire, which is the sticking point in the search for a female version of Viagra and the reason why no one wants to date monkeys. Or, it would seem, from anecdotes in the book, nice guys. To support his theory, Bergner finds case studies of women who feel guilty for not fancying the sweet, reliable men, opting instead for the unreliable risk-takers.

This is not a new narrative; Fifty Shades of Grey and its impersonators deal in exactly these cliches, but Bergner's point is that they titillate women by aligning more truly – which is to say neurologically – with their sexual impulses. Here is a woman with a nice fiance, a guy who holds not only her hand, but her granny's hand, but who she doesn't want to have sex with because she's so busy fantasising about her dashing and dangerous ex. The author extrapolates species-wide lessons from this, about female desire for male-pattern sex, but surely there are other readings; that the fiance, in his "niceness", is communicating a subtle inadequacy; that the desire for Fifty Shades fantasy sex is compelling precisely because it is taboo, and therefore as much a social as an animal impulse.

The solid point is that women's sexuality is still bound up in strict ideas about evolution. As Helen O'Connell, an Australian urologist, puts it, "it boils down to the idea that one sex is sexual and the other is reproductive". Which is why, perhaps, overt sexuality in women over child-bearing age, or 35 in Hollywood, is not considered attractive, while Robert Redford can still play a romantic lead. Bergner is good on this, the politically motivated promotion of some scientific theories over others. "Why," he writes, "from beginnings in equally obscure academic publications, had parental investment theory come to permeate cultural assumptions over recent decades while monkey realities remained much less known?"

Parental investment theory is the strand of evolutionary psychology that argues women are inclined towards monogamy and "safe sex" for the protection of their children, while men, for equally good evolutionary reasons, are compelled to scatter their seed far and wide. But, Bergner writes, other studies undermine this completely, showing that in feral environments where male monkeys randomly kill babies in the group, a female monkey who has sex with as many males as possible obscures paternity of her child and stands a better chance of every male in the group protecting it. Or, in certain monkey societies, the female is dominant, a sexual aggressor who instigates sex and appears to want more of it than male monkeys. "Female rhesus monkeys run the sexual show, incite warfare, and rule the world of rhesus politics."

The causation in these examples can sometimes feel a bit flippant, particularly when it comes to rat motivation: a female rat who runs away from her partner is said to do so in order that "the sex didn't end too quickly for her". (Women readers could write in with alternative explanations.)

And the potted social histories are cursory – from Freud to Madonna in a single sentence, and a summary of Victorian "nascent feminism" that aligns it with Christian evangelism to explain how women came to be seen as society's moral guardians. Without wider social or political context this is practically meaningless.

The lives of modern women fare better, particularly in a good section on the huge and growing problem of antidepressants; 15 million women in the US are on mood-stabilising drugs, a common side effect of which is reduced sex drive. And Bergner is touching on the difficulty of sustaining interest in a partner over the course of a long marriage. It is enough, he writes, to make a sex therapist sigh. (Or rather, to let out "something akin to a sigh, a wordless note of grieving in a lower octave".)

One woman likens the pleasure of having sex with her husband to "the pleasure of returning library books". Another says, "my husband feels like my brother". These sections are a welcome relief from the rats and a reminder that reading life through brain chemistry will get you only so far.

• Emma Brockes's She Left Me the Gun: My Mother's Life Before Me is published by Faber