The Steiger Effect

"The Steiger Effect" is a science fiction short story by Betsy Curtis. It was first published in Analog Science Fiction in October 1968.

Synopsis
Human merchants sell internal combustion engines to a planet whose inhabitants view the devices as magic — and when the humans leave, the engines stop working, because internal combustion only functions in the presence of a psionic field unknowingly emitted by humans.

Reception
"The Steiger Effect" was a finalist for the 1969 Hugo Award for Best Short Story.

Galactic Journey noted that "'Humans secretly have psi powers and don't know it' certainly sounds like a plot tailor-made for [Analog editor] Campbell", and observed that the aliens' social stratification ("Men" who use their minds, and "Boys" who use their muscle) was uncomfortably evocative of "antebellum days in the American South".

Title
Historian Maggie Thompson – Curtis's daughter – has described the story's premise as "there are people who have a sort of 'repairing field' [said Steiger Effect] around them – which is why, for example, your car runs fine when you have it at the service station but renews the grinding noise after you've driven away", and noted that "[o]ur local service station was run by Mr. Steiger."