“Doodle like da Vinci to strengthen your memory and beat creative block,” recommended the email from Cass Art that recently dropped into my mailbox. Along with colouring, doodling is the latest relaxation fad for stressed adults. Is this just another example of our society’s infantilisation, or is there more to it?

Doodling was once a serious business. The dots, stripes and squiggles found on prehistoric cave walls are assumed by archaeologists to have had a religious significance for the Stone Age communities that made them, representing divine mysteries in graphic form.

With the ancient Greeks, though, divine inspiration became more selective and the myth arose of the artist genius blessed with a unique creative insight. In our own more inclusive age, this myth has lost traction. The new cultural orthodoxy is that we are all artists now: an ideal climate in which to mount an exhibition of the forgotten doodles of Georgiana Houghton.

As the show’s title tells us, the 21 watercolour drawings in “Georgiana Houghton: Spirit Drawings” at the Courtauld Gallery (until 11 September) are doodles with a difference. Houghton (1814-84) was an ordinary Victorian middle-class spinster before the premature death of her younger sister, Zilla Rosalia, in 1851 prompted her to take up table-tipping.