In the bad old days of psychotherapy, the therapist would feel the skull and determine a personality from the various bumps and ridges over the cranium.
"The theory," said Mac Buck, editor of App World! magazine, "is that the brain's various control centres would be bigger or smaller depending on how prominent they are."
It sounds like a good theory until neurologists realised that the outer layer of the brain is mainly memory.
"Nobody uses phrenology any more, but it's still popular," said Buck. "Like whipping herpes sores with a hazel twig to cure them. Some people will believe anything!"
As phrenology is still so popular, it is expected that French Applelet company, Le App, will have a winner on their hands with their latest creation, iBump.
"iBump is actually quite entertaining for an hour or four," said Buck. "You start the app, then run the screen over the scalp in a set order, and the app calculates your personality."
The app, available from the iStore for a mere £1.79, takes information from all the bumps and dips and applies ancient phrenology techniques that date back to the Ancient Greeks, to work out the various facets of a personality, before giving a single word description of the person.
"I ran it over my head, and it gave various bar graphs for such personality facets as gregariousness, exuberance, fiscal ability and the like. Most of which I had to look up, which explains my low score on verbosity."
Although Buck generally liked the app, he did have one reservation.
"After performing the test, my one word was 'Gullible'," he said.