Traditional ideas about red-haired people are not complimentary. Physically, they are said to sweat easily, bleed copiously, have a strong foxy smell, and such bad breath that they can raise blisters on other people simply by breathing over them. Morally, they are expected to be ‘bad children’ who cause nothing but trouble; they will be hottempered, treacherous, and highly sexed. The medieval notion that Judas, Cain, and Mary Magdalene were red-heads arose from these beliefs, and helped to perpetuate them. They carried over into conventions for stage villains; Shylock was regularly given a red wig, as was Mephistopheles in Grattan's Faust at Sadler's Wells in 1842.
It is held that meeting a red-head brings bad luck; when first footing is done at New Year, they are unwelcome (Harland and Wilkinson, 1873: 225; Opie and Tatem, 1989: 325–6). On the other hand, their fighting spirit is admired.
Families where red hair is frequent are often said to be descended from the Danes, from the Scots, or from Spanish sailors of the Armada—all formerly enemies of England. If only one child has this colouring, it might be vaguely ascribed to ‘bad blood’, or, more specifically, to the mother's adultery—nowadays, it is usually jokingly said, ‘with the milkman’. Another ‘explanation’ is that the parents had made love during the woman's period, thus breaking a powerful taboo. This does not appear in standard English folklore collections, presumably because of its unseemly nature, but was known, and used as a taunt, in Kent and London in the 1950s and 1960s, and is remembered by some elderly nurses [JS]; French parallels prove its authenticity (Gélis, 1991: 14–15). More frivolously, it is said that if two women pour tea from the same teapot, one will have ginger-haired twins.
N&Q 12s:2 (1916), 128, 196–7, 239, 379;12s:5 (1918), 194, 218;Roud, 2003: 374–5.