The Seat-Saving Sofa Cushion

Every household has one. The seat. Not a seat, the seat: the end of the sofa nearest the lamp, with the best view of the television and the armrest worn to exactly the right softness. Nobody has ever officially been assigned it. Everybody knows whose it is. And every evening, when its rightful owner comes back with a cup of tea, somebody else is already sitting in it.

The Seat-Saving Sofa Cushion ends this quietly. For its first two weeks it simply learns. Thousands of tiny pressure pads record the precise shape of whoever sits there most often: the angle of the lean, the tuck of one foot, the particular way that person sinks down with a sigh after a long day. From then on it knows its owner as well as a dog knows a familiar set of footsteps.

When anyone else sits down, the cushion does not beep or buzz. It inflates. Slowly, gently and with enormous patience, it rises by about a centimetre a minute, tipping the occupant ever so slightly forward, until after ten minutes or so they find themselves perched on the very edge of the sofa, wondering whether they might be more comfortable somewhere else. They always decide that they would.

The deluxe model adds a small speaker that clears its throat. Early testers found this more effective than any spoken message, and considerably harder to argue with. A guest setting lets the owner nominate a visitor who may use the seat for up to three days, after which the cushion begins, very softly, to hum.

There have been problems. In homes with two strong-willed owners who both believe the seat is theirs, the cushion has been known to spend the entire evening rising and falling like a slow sea. One family reported that their cat, having sat in the seat every day of the learning period, is now the cushion's registered owner, and that nobody else has been allowed to sit there since. The manufacturer describes this as working as intended.

The joke rests on something very real. People genuinely grow attached to particular spots, especially at home, and the favourite chair is one of the most familiar examples. Psychologists who study how people use space call places like this territories, and they distinguish between primary territories, such as a home or a bedroom, which we feel belong to us, and public ones, such as a park bench, which we only borrow for a while.

We also share a whole quiet language for holding a place without saying a word: a coat hung over the back of a chair, a bag left on a train seat, a towel spread over a sun lounger early in the morning. Most people read these signals instantly and move on without any fuss. The cushion only does what a jumper draped over an armrest has always done. It just does it with a little more air.