Fictional personality tests: phrenology and physionomy

First some definitions: Phrenology is a 19th century pseudoscience, much used to justify racist and sexist ideas about people's abilities and character by a process which involved fondling their skulls. Physiognomy, the analysis of personality based on appearance, is older since it dates back at least to ancient Greece, but of equally dubious validity. People have mistrusted it for centuries and other people have gone on using it regardless.

18th and 19th century authors made much of their physionomic character studies, but I prefer to quote from a revival, Susanna Clarke's fantasy, Jonathan Strange and Mr. Norrell, set in 18th century Britain. Here is Childermass, whose presence as a secondary character runs through the novel:

He was a dark sort of someone, a not-quite-respectable someone who was regarding Mr Segundus and Dr Foxcastle with an air of great interest. His ragged hair hung about his shoulders like a fall of black water; he had a strong, thin face with something twisted in it, like a tree root; and a long, thin nose; and, though his skin was very pale, something made it seem a dark face - perhaps it was the darkness of the eyes, or the proximity of that long, black greasy hair.

I expect anyone can tell Childermass's appearance is being used to arouse our suspicions against him. The racial stereotyping may be less obvious to anyone unfamiliar with 18th and 19th century discourse on British ethnicities. I've read enough to recognise a representation of the supposed Celtic type, dark-haired and eyed, 'sallow' of skin, a supposed remnant of a primitive and inferior race, clinging on to the margins of British society after invasion by those who considered themselves the British mainstream. Yeah, that's what they thought. As the Wikipedia article on phrenology notes, the pseudoscience of phrenology never really took off in Ireland, due to ...

...not only the Vatican's decree that phrenology was subversive of religion and morality but also that based on phrenology the 'Irish Catholics were sui generis a flawed and degenerate breed'

Now we've pretty much abandoned our belief in physiognomy and its offshoot, phrenology, an author's 'drawing' of their characters' appearance tends to be more cursory. Here is one from another book I read this year, the introduction of the Marquis de Carabas in Neil Gaiman's Neverwhere.

He wore a huge dandyish black coat that was not quite a frock coat nor exactly a trenchcoat, and high black boots, and, beneath his coat, raggedy clothes. His eyes burned white in an extremely dark face. And he grinned white teeth, momentarily, as if at a private joke of his own, and bowed to Richard, and said, 'De Carabas, at your service, and you are...?'

In the 20th century, De Carabas expresses his personality through his choice of clothes, his expressions and patterns of speech. Some cursory details of his appearance are given, but if you blink, you may miss the fact that he is supposed to be black. I've talked to people who did. It's an awkward situation because the inclusion of racially diverse characters was obviously a goal of Neverwhere, the TV series, and all they had to do was cast appropriately. With nothing but words to work with, the novel simply can't harp on about Carabas's appearance - the shape and colour of his face isn't supposed to tell us anything essential about him, and would almost inevitably come out sounding racist.