Hands are tricky things. You might assume that they are entirely on the side of virtue, reaching for sustenance from the supermarket shelves, tapping out serviceable prose on the keyboard, soothing a fevered child’s forehead or stroking a lover’s back.

But that’s only when they’re obeying orders which, it turns out, isn’t often. Left to their own devices, hands ceaselessly return to the body’s surface, where they make all sorts of moral and social mischief – plucking at scabs, picking at noses, straying towards the genitals for a comfort fumble. It’s for that reason, says author Darian Leader, that we spend so much time playing with our mobile phones in public: continuously swiping at a screen in the company of others is just about acceptable, playing pocket billiards really isn’t.

Leader is a psychoanalyst with a sideline in smart, elegant books that explain us to ourselves without using the jargon of clinical literature. In this case, he wants us to think about how central our hands are, not simply to our bodily competence – opposable thumbs really do make a difference – but to our psychic formation, too. Above all, hands give the lie to our fantasies of autonomy and self-determination. We might like to think that we are in charge of ourselves, steering our bodies through the jostling world like a sleek racing car, but the naughty hand is always there, waiting to indulge in a bit of obscenity on the side. This is why so many old horror films depend on the trope of the “alien hand” , a delinquent body part that slashes and murders while its owner smiles benignly, carrying on passing the port and playing the church organ.

And it was always thus. Long before Freud entered the picture, fiddling with his pipe paraphernalia and muttering about the unconscious, experience told us that hands were the part of the body most likely to trip us up. Drawing on the work of the post-war sociologist Norbert Elias, Leader shows how the 16th-century court evolved new codes of politeness, especially at the dinner table. Instead of reaching out and grabbing what you wanted, picking your teeth or wiping your nose on your palm, good manners now required you to wash your hands before dinner, pass the plate to other people first and wait until you were out of sight before scratching your behind.

In the following century, technology expanded so that hands were given little tasks in order to keep them out of mischief. Now smart men and women fiddled with fans, swung pomades, fluttered handkerchiefs and opened and closed snuffboxes more times than was strictly necessary. All these activities, suggests Leader, are analogues of today’s mobile phone finger swipe.

None of these hand-pacifiers, though, had anything on cigarettes. Throughout the 20th century you could sit alone in a pub with some gaspers and seem less an object of pity than an image of enviable self-sufficiency. In this scenario the packet of fags became a kind of “transitional object”, allowing you to negotiate stylishly the boundary between self and not-self. Above all, it meant that you could be elsewhere in your head while staying put physically. Leader uses the past tense here because we increasingly live in a post-smoking world. But it is surely no accident that, just at the moment cigarettes disappeared from public view, mobile phones arrived to fulfil that same hand-busying, mind-travelling function.

Unsurprisingly, Leader writes most confidently when he circles his home patch, which is the consulting room. One of the best sections in this short book, which is really a long essay, concerns the way that psychoanalysis has always privileged the mouth over the hand. This, thinks Leader, is a shame. For while it’s true that the first stimuli an infant encounters are oral, and involve sucking and biting, it turns out that the hand is never far behind. Indeed, Leader explains that “to taste” and “to touch” were once semantically identical, which explains why in early art Eve is seldom shown munching on an apple, but rather holding or reaching for it.

In any case, as the child becomes mobile and ceases to feed from the breast, it is the hand that provides the essential connection with the mother. It is, though, a tie that binds as well as saves. Could that be the reason why so many action films include a scene where someone is dangling over a cliff, hanging on to life only because someone is holding them by the hand? And could that be why, as spectators, we both long for the protagonist to be pulled to safety but also, perhaps, be allowed to separate by plunging into the valley below?