You’ve probably had the experience of encountering a door handle that doesn’t work the way it should – for example, it has a handle that looks like you should pull, but in fact you need to push. In the “real” world, objects communicate to you about how you can, and should, interact with them. For example, by their size and shape, some door knobs invite you to grab and turn them; other door knobs invite you to grab and pull; the curved handle on a coffee mug tells you to curl a few fingers through it and lift it up. A pair of scissors invites you to put fingers through the circles and move your thumb up and down to open and close. Psychologists call these cues “affordances”.