The Walkman also exploits a clear psychological heuristic, or rule of thumb – ‘the jack-of-all-trades-heuristic’, whereby we naturally assume that something that only does one thing is better than something that claims to do many things. Similarly, when we hear ‘sofa-bed’, we instinctively think of an item of furniture that is not great as a sofa and not much good as a bed, either. And some of you may have encountered a spork, an unsatisfactory spoon, which is rather less use as a fork.
