If you describe someone as a chameleon, you probably mean that they’re great at blending in, at changing their behaviour to suit different social situations. You probably don’t mean that they make their heads really bright when they’re about to get in a fight. The latter, however, would be more fitting.

Chameleons are famed for their ability to change colour, and people usually assume that this helps them to camouflage themselves from predators or prey. But in 2008, Devi Stuart-Fox and Adnan Moussalli showed that chameleons probably evolved their dynamic palettes to be social rather than secretive, to stand out rather than blend in.

The duo studied 21 species and sub-species of South African dwarf chameleons and found that those